Copyright, 2013, R. Fleischer
covers lamp theory, lamp substitutions, updating the /5
headlight, adding relays, fuses, LED
instrument lamps, large
headlights, special sockets, heavier gauge
wiring, HEADLIGHT MODULATORS, flasher, ETC.
This article does not cover HID nor LED HEADLAMP lamp substitutions, although I DO discuss them a little bit. I believe that LED headlamps are NOT at all ready for prime time; and there are plenty of problems in using HID headlamps, particularly with turn-on times, when going from low to high beam and the high beam is HID. There are also reflector and focusing problems that are severe. The stock reflector and lens are not OK for HID conversions of just the LAMP!
see article 24B, that discusses the headlight relay, the internal
the handlebars switch, and how they all work together. It is NOT so simple,
and that article information IS needed to understand using larger wattage
lamps, relays, ETC.
Part 1, Headlight lamps, and a little on relays and switches:
NOTE: Our Airhead bikes use 9003 type headlamps, often just called H4 halogen lamps, and sometimes identified as 9003HB2. There are some differences in these lamps, particularly in specialty versions, but I don't need to do a 5 page dissertation on them here.
BMW stock lamps are arguably quite decent for
your bike; except for the UNconverted non-halogen
early /5 headlight lamp
assembly, which used a 40/45 non-halogen lamp, and is
vastly improved by upgrading the lamp, lens, and reflector
H4 halogen lamp; by
using the original BMW conversion kit parts;
or, cheaper, from an
R65;....or using a special
which is a 60/55 Halogen, made by Osram, and that lamp's particular construction and filament will work with the stock /5 reflector and lens. The stock /5 headlight socket will accommodate a higher power lamp with no problems. Substituting a standard H4 lamp with the original lens and reflector will NOT work well, the lamp may not fit the hole well, and the light pattern will be ugly in many ways. The kit that BMW once offered to upgrade the /5 headlight is NLA, hence the recommendation to use the R65 assembly. This will adapt at much less cost and works well with common H4 halogen lamps. The stock 180 watt /5 alternator is adequate. It is possible to update the /5 alternator to a 280 watt unit if one has lots of electrical needs, but only a specific size (105 mm stator) fits the /5 engine casting, and that particular stator housing is from some of the 1974-1975 model years. However, a high powered alternator to fit all airheads, including the /5, is available, called the EnDuraLast....available in 105 mm size for the /5, and 107 mm for later models. You can also consider the Omega alternator which has even higher output....even though both are seemingly rated at 450 watts (I have an article on this website that describes their REAL output).
NOTE that the early headlight chrome rings
were not screw/clamp fastened, and many have been lost along the
road, and it is best to
fashion a method to secure them at the
very bottom if you are using them.
It is up to YOU to decide, for one reason or another, to make a substitution or change or modification. Perhaps you are on the road and cannot find the correct lamp. Perhaps you want them brighter or want to add a lamp. Note that some lamps are ~direct equivalents, such as the 9003 headlight bulb (for after the early /5, or the converted /5)...and there are subs available for taillights, instrument and
indicator lamps. Many substitutes will fit in existing sockets and are quite adequate for use. When substituting a lamp it is a good idea to THINK about such things as life expectancy, light output, AND heat output.
Be aware that while the 9003 is a generic number, the Euro lamp versions are generally of better quality, light pattern and output.
At this point, after you read the
above sentence, I thought it appropriate to give you some nerdy headlamp
International specifications are not the same for the H4
headlamps as USA specifications. You will find the information in
to be generally hard to come by. International H4 lamps are rated at
1650 lumens on the high beam and 1000 lumens on the low beam,
both are +- 15%. Note that the specification has a maximum power drain,
and it is 75 watts on high beam and 68 watts on low beam, and
these specifications are for 13.2 volts. That 13.2 volts is more important than a quick glance tells you.
For the USA, the equivalent lamp is called a 9003/HB2 or H4, and the lumens are 1580/910 +-10%. The draw is specified as maximum 72/65 watts but at 12.8 volts. You will find the drain about the same or higher at the European 13.2 volts. If you are 'lucky' your bike's system has a voltage of closer to 13.8 to 14.2 AT THE LAMP. This raises drain in watts, but increases light output, but decreases life, rather by a fair amount too. HOWEVER, the decrease in life on regular incandescent lamps, with increase in voltage, while rapid, is not nearly so rapid as with a Halogen headlight lamp bulb.
Note carefully what I am saying here. A regular incandescent lamp, such as nearly every lamp in your motorcycle (except the H4 or other Halogen headlight) will have a life that goes down on a steep curve, as voltage rises, particularly if over rated voltage. BUT, in the other direction, a quite modest DEcrease in light is had with a QUITE MODEST DEcrease in VOLTAGE, YET...YET!...that results in a HUGE increase in LIFE. The Halogen lamp is much less affected in these ways.
I have formulas for lamp outputs, and how they vary with
voltage, and information also on the difference between Euro and USA
specifications for voltage, light output, life, etc. But, I think it
easier to just simplify it all for you:
The below information was for a 9006 lamp, but the idea is common to all lamps.
This listing is for a USA specified lamp.
10.5V : 510 lumens
11.0V : 597 lumens
11.5V : 695 lumens
12.0V : 803 lumens
12.5V : 923 lumens
12.8V : 1000 lumens ←Rated output (USA)
13.0V : 1054 lumens
13.5V : 1198 lumens
14.0V : 1356 lumens ←Rated life (USA)
14.5V : 1528 lumens
NOTE that the lamp output is rated at 12.8 volts. Most lamps will have considerably more voltage on them, especially if the alternator is charging, or the bike is just at the JUST-stopped point, and the 12.8 volt rated rear braking lamp is being considered...the voltage might be much higher for awhile. NOTE that some manufacturer's rate the lamp life at the rated voltage. Thus, 12.8 for output and life. It is extremely difficult to get the information.
The Europeans are more realistic with voltage ratings; they use 13.2 volts for rated light output.
When operating voltage drops to 95 percent, headlamp bulbs produce only 83 percent of their rated light output. At 90 percent, you only get 67% of normal light output.
at 85%, about 11.2 volts, you get HALF of normal light output!!
You may find some books stating that a 'standard' H4 lamp is 1100/1500 lumens. Disregard that statement.
There is an enormous amount of false advertising and hype about aftermarket headlight lamps. I will get into this deeper later. Suffice HERE to say that PLUS type lamps have a slightly different focus point, REDUCED life, but the focus is further down the road.
The BMW 55/60 watt halogen H4 headlight lamp (similar to common type 9003 and really same as BP1260-H4 and generally equivalent to 9003/HB2) is often changed by owners to much higher wattage units. Be very cautious about this, as not only is the airhead alternator output not overly generous, but the handlebar light switch is NOT rated for those larger lamps, and therefore it is a MUST to use a heavy duty relay (the autoparts store Bosch 20 or 30 ampere relays are not expensive and are fine for this), using the original light switch output connected to the relay coil. You can do this conversion with ONE relay, if that relay is "SPDT", which means Single Pole Double Throw. The Eastern Beaver company makes nifty relay kits, that PLUG IN!...but I am not a fan of them for higher than stock power lamps, feeling that the contacts in these relays are not heavy-duty enough, although, to be fair, their kits DO seem to hold up just fine. No hard and fast rules here on how to wire and use the relay(s) and switch gear, installations vary, depending on what you want to do/have. I will have more to say much later in this article.
Eastern Beaver also has ceramic sockets available, that handle high temperatures. Here is a hyperlink, you will have to scan down to find the ceramic one: http://www.easternbeaver.com/Main/Elec__Products/Connectors/Headlight_Connectors/headlight_connectors.html
They are not the only company selling such high temperature sockets. A discussion of sockets, and other recommendations, is later-on in this article you are reading.
probably have an airhead with the high beam flashing switch on
the left end of the handlebar. That switch
is part of the
Hi/Lo selector. You really do need to be aware of a
peculiarity. The Hi/Lo switch section, in the stock
bike wiring, handles the headlight's full current flow. That is why one or
two relays are added if you install a headlight
that is over
maybe 70 watts, so that the switch does not wear out
quickly. BUT, the push-to-flash section is a
partially separate circuit.
Thus, just how you wire up your
relay (s) is important.
Phillips makes what they call and Xtreme Power lamp, stock wattage, that puts out 1895/1150 lumens. It is a decent lamp.
The best 'nearly stock' H4 lamp I have found, to be used with stock or with one or two relays, is the Osram lamp 64205, it is rated at 70/65 watts. It has a very nice output, at 1350/2000 lumens. Very well made lamp, and just perfect on the beam and color. I think it will generally be OK to use this without adding a relay(s), but relays will improve light output and greatly lengthen switch life.
Brighter is the higher powered 64206 at 80/85 watts and 1750/2400 lumens. The standard legal lamp is 64193 at 60/55 watts. The rated life for these lamps is 100/200 hours when at 13.2 volts, under normal automotive type use. Expect somewhat less on a vibrating bike...but this depends a lot on the bike.....and especially on the voltage. If the voltage AT the lamp BASE is more like 12.5 or so, then the lamp will last a MUCH LONGER. THE REVERSE IS TRUE, the lamp life going DOWNward, very fast too, for a rather modest increase in voltage. Lamps, when considering the rated lamp voltage, have a relatively small light DEcrease with a small voltage DEcrease. If your lamp runs at 14.2 volts, the lamp life will be shortened, but, frankly, I prefer that voltage for lamp performance, and don't mind the life DEcrease...which is not that bad, and a headlight modulator (on the high beam) probably EXTENDS the life somewhat. My comments about voltage and life applies for sure to smaller incandescent lamps and non-halogen /5 headlamps. Due to a peculiarity of how H4 Halogen lamps work (redeposition of material back on filament, etc, and
that the temperature of the filament MUST be adequate for this to work well), the LIFE of the lamp with voltage changes is NOT nearly as severe as with smaller non-halogen lamps. Halogen headlamps will last a goodly number of hours on a motorcycle, if the voltage AT THE BASE of the lamp when the lamp is ON, is 13.7 to 14.3.
Here is a place that seems to stock these lamps; I have no experience with the company:
This is how an H4m, 9003, etc., lamp is internally connected.
In actuality, it applies to just about all similar 3 terminal lamps.
The blue lamps and other high priced trick
lamps may SEEM brighter, but if you are in an oncoming car, you
may think differently.....claims
of 100 watt output for 55 or 60
watts of power are dead flat wrong and TOTALLY misleading.
PIAA is one of the worst cases, their advertising is, in a lot of instances, bogus. The eye is much more sensitive to certain colors. The eye's sensitivity to yellowish-green is quite interesting, but we do not have headlights of that color...because, while the light would be very visible and very noticeable to the drivers of other vehicles, the light would not illuminate the ground/highway/etc., for the driver of the car with those
yellow-green lamps. It is altogether way too easy to confuse the buying public with claims that are either unproven, downright incorrect....or, that mix up these two things:
1. illumination of the road, etc., for the DRIVER.
2. illumination of the oncoming vehicle for recognition.
Those two items are NOT ONE AND THE SAME THING. AND...the blue-lamp (etc) makers, like PIAA, are definitely taking advantage of the confusion, in order to sell you a lamp. In FACT, you may even THINK that their stock 55/60 blue lamps are BETTER and BRIGHTER....yet, they are actually LESS so.
Our brains are 'annoyed' MORE by some 'colors'....which, at the same time, may....and often do NOT ....provide better clarity, visibility, etc. "The" prominent example is the bluish light from blue-coated H4 and H3 type lamps. The light output is not nearly the same from those bulbs as the spectrum of light from modern HID lighting in cars; which they were designed to SEEM to copy. The blue coating lets more blue of certain frequencies through...but greatly removes the amount of wider spectrum light that might give YOU, the driver of that vehicle, more information about things the light lands on. But, to your brain, just looking briefly at the lighted area, especially if the beam is focused differently, particularly narrowing the beam in some particular portion...may 'trick' you into thinking that the blue lamps are better than the
clear ones. THAT is the sneaky thing about these blue-coated lamps.
Some manufacturer's will also change the guides and director metal bits inside the lamps and provide what you THINK is brighter light, but is a different dispersal.....and the beam cutoffs barely are legal. Some are not legal....some have too much power and are illegal...and some have almost no, or actually no, beam cutoffs, and are very illegal, and blind oncoming drivers. There were some lamps being sold that changed the FOCUS point, by changing the distance between reflector and lamp light emitting element....not sure if those are still on the market.
In some instances the better quality European-spec headlamp bulbs are noticeably better than the cheaper domestic lamps. The BEST lamp I know of, and not sure where to buy them anymore, is the Osram 64205....I think it was a 70/65 H4, at 2000 lumens high beam and 1350 on low beam. Very well made lamp, and just perfect on the beam and color.
The blue coated PIAA lamps (and their many imitators) are awful; and most have no idea, and think them better. It is proven by many tests of many types...which is likely contrary to what some of you think. AND...I don't blame you for thinking that way....even if NOT influenced by the advertising.
****Headlight bulbs run very hot, and the H4 halogen lamps use a type of quartz glass that you must NOT touch with your fingers, which leave often invisible skin oils on the lamp, which shorten the lamp life. If you have handled the lamp glass, clean it with alcohol. This is a good policy for any lamp.
****The stock headlight lamp
sockets are perfectly capable of handling the stock lamps (and, the /5 only socket will handle
higher powered lamps); however, when you increase the wattage of the headlight lamp (and you'll use relays, riiiiight!!??!!)...then
you are advised, for /6 and later, to use a socket that handles more heat. The /5 socket was 63-12-8-650-145. A substitute could
be the NAPA LS6235, around $6.
That number is listed in Napa literature now as under the ECHLIN electrical's section...and
the Napa number in the catalog is ECH LS6235. It appears to be bakelite and have ~14 gauge
wire, 3 each black, maybe 6-1/2" long.
marked on the socket. It seems well constructed.
Another socket is the Autozone 84790, called a high
socket....I was told it was ceramic, which would
be the best way to go (if it is....but someone reported to me
that it is
actually 482°F nylon; 3 colored wires, and a rubber
boot is included)...that would be OK, but I have not tested the
Here is another source, scan down for the ceramic socket:
Headlight reflectors and inside the glass,
will get fogged up by dirt, etc., over a long period of time, and
should be cleaned with alcohol
mixed with a drop of detergent and
in some water, and using appropriate lint-free cloth, and then flushed with clear water.
to dry VERY thoroughly before
lamp, etc. I do
not try to separate the
glass part, I do my cleaning through the lamp hole. I recommend against using Windex or similar, with ammonia!
Keep in mind that an incandescent lamp has a very hot piece of metal inside, and that metal will radiate HEAT. The wattage rating of a lamp is the power INput to the lamp, and that power is directly proportional to HEAT. Some lamps are rated only in voltage and current. Multiply voltage times amperes to get watts. It is possible that too powerful a lamp will do some heat damage to your lamp socket area. In fact, that is QUITE possible. I have theorized that using some larger lamps have SO MUCH extra heat they are not only going to melt or deform the plastics in the area, but may well detract from life of such as the tach and speedometer/odometer. The later HEADLAMP sockets are not good with large lamps...early ceramic ones are fine. I have NOT tested all the possible combinations of higher wattage lamps for any heat or other problems in the instruments, nor eyebrow area of the RS/RT. ...which I THINK can be used with most 5 watt lamps...but unlikely with 10 (??).
LED's (Light Emitting Diodes)
Bright 12 volt-rated LED lamps that fit the indicator sockets on some BMW motorcycle pod models are now available reasonably priced. However, some give insufficient light output on any sort of angle, and many do not mount in the original sockets....some that do ARE available.
Many LED lamps do not project much light to the sides and they do not work in
flasher circuits in which the flasher
unit is load dependent,
additional changes. BMW has used a number of
different flasher circuits on our Airheads. Some 12 volt LED 12
volt lamps, or lower voltage ones with added
resistors, work just
fine on most /6 and later bikes. Many types of LED's and multiple LED lamp
assemblies are available commercially. BE
their use, especially for the rear tail light which is a big
safety item. There
are some LED lamp arrays that
project to sides and
forward, and I have seen some that were
quite good for the turn signals, and even in use for converting to
combination turn/running lamps.
SOME, however, don't work well when the turn function is on, because it is not all that much brighter, although the specs say they are, than the running portion. Specs are helpful, but REAL world LOOKING is important here. It is IMPORTANT that a running/turn lamp be distinct from RUN, in the TURN mode.
Modifying to LED instrument lamps is not necessarily always
an improvement. It is pretty easy to remove a pod and
replace lamps every
few years anyway. You hardly save much
in wattage doing a LED conversion. It is true that a LED lamp usually
lasts almost forever, if
It may, however,
be hard to see, especially in the daytime. Some have almost a dot type
Many have converted various rear lamps to LED. NOTE that a power-wasting resistor may be needed on SOME. Think before you jump in! For extra lighting, consider a license plate frame that has LED lamps all around it, in particular the type that operates as RUN mode AND a braking mode.
NO LED headlights that I have seen are OK...so far, for Airheads! I expect that some will be available, at a high price, in the near future, but using them in the stock reflector may be a real problem.
I have the same idea about CONVERTING the stock headlight reflector and lamp assembly to HID...although some are fairly decent.
stuff on lamp life,
***NOTE that if your bike has one stock rear running lamp, and it fails, you have NO light to the rear...at all, unless you have running lamps that have been added. Conversion of the turn indicators to have an additional running lamp function is relatively easy, and an article is posted at this website: addingrunninglamps.htm There are pros and cons to this conversion. The strongest argument AGAINST the conversion is that the turn signal portion MIGHT NOT be AS visible, when the running lamp is illuminated. You can select a running lamp wattage that is relatively low, to mostly offset this argument.
I prefer separate lamps in many instances.
When a common lamp fails it is almost always
because the filament broke from being thinned or
stretched/sagged, all from usage, over a long
time. You can generally identify a lamp that is close to dying as the filament is visibly sagging. This is
noticeable in the turn
signal and taillight and braking lamps. Thus,
regularly, you should visually inspect the lamps. This
is highly recommended
for the rear running and
Sudden failure is usually brought about by a characteristic of the wire filament in incandescent lamps. ....
The internal lamp filament wire, a type of tungsten, has a far lower resistance when cold, than when hot. Thus, at the instant the power is applied to the cold lamp filament, the 'inrush' current is very large, and the thinned or otherwise weakened area of the filament fails. As the wire breaks, if the spacing between the broken ends is small enough, and the time that small spacing exists is long enough, the lamp might arc. The lamp MIGHT draw a large current at that time....and in RARE instances, blow a fuse. This effect is FAR more prominent in higher voltage lamps, such as in your house, where the breaking is accompanied often by a bright flash of light due to the arcing (but seldom blows a fuse or circuit breaker. NOTE that when the turn signals are flashing on and off, that on-off usage detracts greatly from their official life expectancy. Strangely, not so with the Halogen lamps...if flashed at a relatively fast rate (such as the 4 times per second officially for a headlight modulator). A very special case is a halogen headlight bulb, where a headlight modulator MIGHT even INcrease its life. For extremely complex reasons, a halogen headlight bulb may last LONGER with a modulator, IF the modulator does NOT allow the lamp to cool too much between 'pulses'. A rate of about 2.5 to 4 per second, even if fully off and fully on voltage is applied, is near the optimum for both life AND eye catching potential! Use of modulators is deemed a strong SAFETY DEVICE by ME, although others dislike them, feeling that they annoy oncoming drivers; and some
have very strong feelings about being in front of someone with flashing lights. Use of proper types of HEADLIGHT modulators are legal in all States, and is codified into Federal Law for motorcycles.
Note also that book values for lamp life are most often based on AC, not DC, and for NO vibration. At least this is so for American numbers. It is VERY UNclear if all vehicle lamps are even rated for DC. Lamp manufacturers do not supply the complete information...even when asked. The rule of thumb on LIFE of lamps rated for A.C., is that the AVERAGE life will be HALF the book value AT BEST if an AC-rated
lamp is used on DC.
GENERALLY, a higher voltage-rated
lamp will last MUCH longer, in a circuit that has LESS
than that lamp's rated voltage, at very little cost in
output. LIFE INcreases GENERALLY at the 12th
(some books say 8th) POWER (yes, exponentially) of the INcrease in the voltage
of the lamp,
above actual circuit voltage. The DEcrease in life if a lamp has excessive voltage applied to it is
vastly faster, percentage-wise.
over-voltage application to lamps means a SHORT
life. The voltage measured AT the rear brake lamp, or
headlamp, or any lamp, is
ALWAYS going to be a bit BELOW the
measured BATTERY voltage, and probably a bit below the fairing
voltmeter....by a typical
0.4 volt OR MORE. THUS, a battery
might be floating during cruising at 14.0 volts, the fairing voltmeter
read 13.7, and the brake light when
illuminated be actually at 13.3 volts. This has an effect on lamp life,
referring to the RATED voltage of the lamp...which is likely 12.8
the BRAKE lamp filament. Typically, then, 12.8 volt rated BRAKE
lamps don't last long. These values are off the top of my
head, not measured values.
To restate this in the reverse direction, if a lamp is being run at a slight DEcrease in voltage than it is rated for, the light output will be almost UNnoticeably lower, but the LIFE will be GREATLY EXTENDED. If the voltage is at a slight INcrease in voltage than it is rated for, the lamp life will be, in proportion, GREATLY REDUCED. Yes, the difference between the effects of higher or lower voltage is NOT THE SAME, proportionately.
NOTE that while life of normal NON-halogen lamps increases continually as voltage is dropped more and more, not so the halogen....which, if filament temperature drops enough, will start to lose life....on a complicated curve, which then, as voltage continues downward, increases life, again. The area of DEcrease is generally under 11 socket measured volts, so is of no real interest, other than my nerdy reply here, for our bikes.
DC (direct current...battery power) operation of lamps REDUCES lamp life as was noted above. Lamps are generally rated by the manufacturer using AC (alternating current) power. It is UNclear if headlamps, or even other vehicle lamps are also rated thusly. Yes, this is peculiar, because many lamps, not just headlamps, are designed for vehicles that certainly do not have AC systems driving the lamps. There are some exceptions...and peculiarities. My old Vespa scooter had DC output for the battery, coil ignition, and taillight, and an AC output strictly for the headlight. I have had antique radios come into my shop that have AC on their dial lamps, and the lamps are original, and the radio has been in use for 70 years.
Put yet another way: if a lamp is used at its RATED voltage, one MIGHT, under ideal, non-vibratory, constantly left on, alternating current operation, obtain its average rated life. If the voltage is lowered by 10%, or the lamp is rated at 10% higher voltage than it is being used at, then the life goes up exponentially. The reverse is true also, BUT the effect is FAR faster! This means that using a lamp
with higher than rated voltage supply to it will reduce life VERY quickly. The measured LIGHT output of a lamp is affected only very slightly, by a 10% change in voltage. However, for headlight use, with halogen lamps, where the effect of lowered voltage is faster on light output, it is sometimes worthwhile to use larger gauge wire, relays, more direct wiring, etc., to raise the voltage half a volt or more...or to protect expensive handlebar switches (particularly with larger wattage lamps). Note that most all modulators DEcrease headlight voltage very SLIGHTLY, decreasing actual light SLIGHTLY....and thereby this modulator usage by simply the SLIGHTLY lower voltage ALSO extends life. This effect is VERY VERY SMALL, however on modern modulators, which do not use older types of transistors (which had higher voltage drops when fully turned-on) to control the through-power.
ONE LAST WAY to think about this: If your
voltage regulator is set for 14.9 volts at 70°F (this is when measured directly
at the battery terminals, and is also
the absolute upper limit
voltage for most types of batteries), you
might expect MUCH less life on your
lamps. They will be somewhat brighter
Probably 14.2 is a nice value for most batteries as a compromise, when one also thinks of battery life (most batteries have a longer life if the charging is set for 14 to 14.4, as opposed to lower voltage). Certainly, the 13.8 that is often found will extend lamp life. You can expect your BRAKE and TURN lamps to have REDUCED life with over 14 volts. I still recommend 14.2 to 14.4 volts for the readings AT the battery TERMINALS...for battery life, etc.
Final nerdy point: A lamp with 50%-100% greater instrument-measured (or specified) light output will NOT look all that much brighter to your eye.
PART 4: Lamp equivalents and/or substitutions (see much earlier for headlamp numbers).
UNDERSTAND FIRST OF ALL THAT SUBSTITUTIONS ARE JUST THAT, AND MAY OR MAY NOT BE TOTALLY EQUIVALENT. Today, one can USUALLY get the original European lamp number at most autoparts stores. However, there can be times you WANT a substitute or have to use one, for a variety of reasons. It may be an emergency burn-out; it may be you want a brighter lamp; it may be you want the better performance of an original type......and many more reasons. When I list a substitute, it means you will have a usable useful lamp. In many instances, below, I describe the differences, and what that means.
Lamps with the Euro part number almost always perform BETTER than the American part that is often substituted! In particular, the BRASS base American lamps do NOT do well.
Various lamps in the airhead can be substituted USUALLY WITHOUT problems.
substitutes for EVERY lamp. Some are OK, some
The Alternator lamp (not the /5) is rated at 12 volts and 3 watts, part number 07-11-9-978-372. The 2825 lamp will offer more brightness, and a bit more alternator output at the lower initial rpm area. You can also use the common #168, etc...see below. There is an article on this website on adding a resistor in case the lamp fails...which usually, otherwise, stops the alternator from ANY output. The article is the genlampresistor.htm article.
The rear running lamp, BMW 07-11-9-978-227, rated at a NOMINAL 12 volt and 5 watts, can be substituted by a very commonly available #97 lamp, which is rated at 13.5 volts at .69 ampere, which means that at THAT voltage, it would draw 9.3 watts, it will draw less at 12 volts.
Regarding the substitution of #193, #194, #168, #161, #158 used in the instruments:
These lamps are described officially as style T 3-1/4 and used at the tachometer, speedometer, turn signal indicator, GEN.
158 lamp = 2.80 watts, .20 ampere, rated 500 hours, a.c. (may be rated at 13v and .24 ampere), about the same light output as a 193 and 194.
161 lamp = 2.66 watts, .19 ampere, rated 4000 hours, a.c. Emergency use only for airheads.
168 lamp = 4.90 watts, .35 ampere, rated 1500 hours, a.c. This is a particularly good sub for the GEN
lamp (/6 and later), as its characteristics ever so slightly enhance the starting of charging.
193 lamp = 4.62 watts, .33 ampere, rated 5000 hours, a.c. (rated at 14 volts too).
194 lamp = 3.78 watts, .27 ampere, rated 1500 hours, a.c.; a bit less light than 168, 1500 hour life..
2825 lamp = This is a 5 watt Euro spec lamp, commonly found in the U.S. .....12 volt rated, not 14 as
above lamps; 0.4 ampere, and brighter than 168 and 194, and very nice, if pricey, replacement for
them. NOT super long life. This lamp develops too much heat, IN MY ESTIMATION, for anything but
the GEN lamp usage.
2821 lamp = 12 volt rated, not 14. 0.25 ampere, light output fair, only a slight bit more than the 194, and
not super long life, but longer than the bright 2825.
ANY of these bulbs will work adequately, the #168 and 2825 being a slightly better choice for the GEN lamp, wherein you want charging at the lowest rpm point where charging begins. Just a WEE tad of help though. You WILL gain more low rpm electrical output by using the latest 2.8 ohm rotor, if your rotor is an earlier version, and use the electronic regulator. For the GEN lamp, one should consider doing the resistor modification which will help charging slightly, and eliminate a charging problem if the lamp burns out (rare as that is). See the GEN LAMP Circuit modification on this website. Be cautious about the 2825 in other areas....due to the heat developed.
In general an E- prefix means European standards, which may or may not be better in some instances and is not overly important.
Instrument lamp: #07-11-9-978-279, 12 volt, 2 watt. This is the hardest lamp to substitute. This lamp
has what is called a PHILLIPS base (BA7S midget Bayonet Base...and a T2 tube...1/4" diameter).
The "BA7s" base is 8.7 mm from top of locating tang to bottom contact, the barrel diameter is 7.0
mm, tube is 1/4" diameter, and the width across the located tangs is 8.6 mm. The ORIGINAL type
of lamp was called a J12V/2W lamp in BMW literature.
Equivalents or substitutes for that lamp:
(1) GE 2696; Osram 3898; Philips 12829. These are all 12 volt, 0.167 ampere, 2 watt, and rated at
(2) It is not clear to me that the Eiko SE1274 would fit. It is 12 volt, 0.125 ampere, 1.5 watt, but the
base is BA7.5..I think...and uses T-1-3/4 shaped glass.
(3) There is also a Narva 101006 lamp, rated at 12 volts, .17 ampere, 2.04 watts.
(4) The BA7s base lamps were also used on some old car radios...and it is possible a repair shop
has some 12 volt lamps.
The following lamps rate their own section in this article:
Turn signal and brake lamps and running lamps, various uses, part numbers, etc:
12 volt, 21 watt
BMW #07-11-9-978-370, substitute is common #1156. The 1156 lamp is
rated 12 volts, 2.1 ampere, some books have it as 12.8 volts,
27 watts, 1200 hours (a.c.) (you will NOT get that number of hours)....which
is a BIT brighter...you probably won't notice. The 1156 lamp is also
available sometimes in both copper and plated bases and
sometimes in aluminum.
The 1156 has two guide pins directly opposite each other
and has a single contact base, and only ONE filament. The Euro
number for a close enough lamp is 7506. The 7506 is RATED at 13.5 volts,
for a "12 volt system".
That lamp is typically called a 21 watt lamp, and the Euro rating is 150 hours.
You won't get that, but it is vastly more accurate spec for life, than the 1200
hours specified for
similar lamps like the 1156, and even some 7506.
The above lamps are used for one-function use, such as just a turn signal, or just a brake lamp. By the way, there is a 6 volt version, which is number 1129.
The 1157 lamp has the pins OFFSET in distance from the base, that is, one pin is lower and one higher than the other. This was done so the lamp can only be installed in one position, and allows the lamp to be used in a dual contact, dual-function arrangement, in which one side of the lamp is much higher powered than the other. The high power section is the brake lamp, the low power section is the running section. This type of lamp is used in conversions as well as original stock use, for such as a low-power running lamp; with a separate filament for a bright braking lamp. In conversions for modifying a turn signal for running and turn use, this type of lamp is used most often.
For practical purposes,
the 1157 lamp is the same or similar to the 2157 and 7528. The 1156 and 1157 and 2157 lamps are close enough to the Euro lamp
equivalents (7506 and 7528) to be used most any time as substitutes. They are NOT true equivalents. NOTE that the European lamps with SILVER COLORED BASES are generally to be preferred over the American brass bases.
For those who have converted their turn signals to ADD a run function, the usual lamp used is the double contact lamp, common #1157 or 2157. The Euro number, better, and also available
at your autoparts store, is 7528.
These lamps vary a bit in the filament rating and light output, but the truth of the matter is that it makes little difference, and how the specifications were done makes this mess a bit complicated. Both the Euro and American lamps are the same size, have the same basic structure, but the way they are electrically and light output rated is a bit different, which makes things confusing. Just go ahead and use whatever one you want. I am well-aware that others think differently.
The 7528 and 1157 & 2157 lamps have offset pins so they cannot be inserted wrongly into the socket. The lamps have two sections, one is far brighter (for TURN or BRAKE) than the other. The sections are: 12.8 volts, 2.1 ampere, 27 watts, 1200 hours; and, 14.0 volts, .59 ampere, 8.26 watts, 5000 hours. If your average speed is 40 mph, 1200 hours would give you 48,000 miles on these lamps. I doubt you will get 10,000. I think a hundred hours might be good! But, that is normal for any highly stressed turn & brake lamps, stock or not. NOTE: some manufacturer's rate the 7528 lamp at 13.5 volts and 1.85 amperes, and the other section as 0.44 amperes.
The confusion occurs when one is dealing with these lamps in DC
circuits, AND in the real world. The 1157 lamp has one filament that is
rated for 12.8 volts, 2.1 amperes, 32 CP, and a supposed 1200 hour life.
You will NOT get that much before the filament fails. For turn signal and
brake lamp usage, that filament is hardly on very long each time you use it, but it won't last a long time.
The lower power filament is rated at 14 volts 0.59 amperes, 3CP, and 5000 hour
life....you won't get that life either.
IT IS THESE THAT ARE THE PREFERRED LAMPS!!!!:
P21/5W lamps are available at your autoparts store, part number 7528 Eiko; or other mfr.
P21W Eiko number is 7506.
Rather often you will find the base of lamps stamped with 12 volts. That is not the lamp voltage rating, but the SYSTEM rating. What makes it even more confusing is that SOME lamp manufacturer's use the 12 volts in determining lamp life (perhaps A.C., perhaps D.C., they don't offer details). A lamp run on 12 volts AC will last terrifically long if it is not in an on-off situation too often, if it is not exposed to vibration too often, and if the REAL voltage rating is 12.8 or 13.5, or even 14.0.
K-bikes: The rear running lamp might
be an old #1077, the present number is 5008, and the lamp is 12
volts 10 watts 0.83 ampere. BMW number was 07 11 9 905 337.
The rear brake lamp is rated at 21 watts, 12 volts 1.75 amperes. The present number is
7506. There is another rating, unlikely to be on bulb not package, and that rating is 25 watts,
13.5 volts, 1.86 amperes. The BMW number is 63 21 7 160 789
Back to Airheads:
The original function lamps, T-1-3/4 style, like #07-11-9-978-375, were 1.2 watts, very close to the #73 long life lamp, or the slightly brighter #74 lamp. One could even use a #37 lamp, which is similar to the 73. Another lamp is the E2723, rated at 2.3 watts. Sometimes these smaller indicator lamps are hard to find, and an electronics supply company may have them in stock. You MAY find the E2723 at autoparts stores, sometimes the others. All these lamps can be used as the high beam indicator, brake light failure, OIL, and neutral indicators. LED substitutes are now available, white output, for these lamps. The power drain is only 0.32 watt, but they are VERY bright...but not all that much of the brightness is fully usable.
The 4 watt lamp 07-11-9-978-256 (the updated BMW number is 07-50-9-063-576) is used in two places, the GEN lamp on the /5 bikes, and in the Parking Lamp position. When used in SOME models in the headlamp REFLECTOR SHELL (on faired RS/RT models no lamp was fitted, but CAN BE), they can be substituted, and also with vastly brighter lamps if wanted. BUT...some might want slightly weaker lamps,
such as the #1893. The #1893 lamp can be substituted for the 07-11-9-978-256. There are a lot of these types of "standard miniature bayonet" lamps, such as 1889, 1895 (round bulb), 1891, 57 (round bulb). Some folks do install these for 'daytime running'. Some folks have a headlight on/off switch, and use the parking lamp to save watts, a 5 watt halogen used here is very considerably brighter than the above lamps, and a 10 or 20 watt halogen is VERY bright. Some Airheads are equipped with a headlight switch (depending on year and model, and Euro or not) that makes it possible to ride without the headlight on....probably illegal for some, but this is done anyway. It is possible to make a small wiring change at the ignition switch and have this 'side of reflector light'...and the ignition....be ON in the PARK position, and the headlight main bulb on in the normal position. Don't use the 10 or larger watt lamps for the RT/RS EYEBROW lamp, use only for the small socket, described, for the HEADLAMP reflector. It may be possible (watch the heat!) to use the 5 or 10 watt halogen in the eyebrow position, but I see no reason to even try that, as you would not want to use that lamp for a daytime headlight function. The eyebrow lamp housing and lense does not like excessive heat. Some have removed that lamp, and wired the eyebrow to the place for the socket on the headlight shell, and used a Phillips Halogen lamp, 10W being 12024; 20 W being 12452. See below for the 5 watt probably OK lamp.
Here is additional information on the higher powered lamps for the headlight parking lamp position (remember, NOT in the eyebrow light of the RS/RT!...they are too HOT!):
Parking lamp bulb socket, in case yours is missing: BMW #62-14-8-680-130. If you want the wiring harness it is #61-12-1-358-176.
Osram Miniwatt #64111, also known as Sylvania
39431, and Philips 12023, halogen, 5 watt. This lamp may be
OK for use in
the eyebrow too.
Osram Miniwatt #64113, Philips 12024, halogen, 10 watt.
Osram Miniwatt ;Sylvania #64115, Philips 12452; Napa-Wagner 47835; Hella 78165; halogen, 20 watt.
NOTE: The 64111, 64113, and 64115 all
are the same size of physical lamp, they use a Euro base style
called a BA9s, and have a 9.3 mm
diameter bulb and MOL
(length) of 33.0 mm. All of these lamps are nominal 12.0
volt rated, and while I do not have life expectancies, I suspect
only a few hundred hours, but may be wrong on that.
Note that these halogen lamps are not overly common,
CONSIDERABLY....even 2:1. You can find them by using Google.com by simply entering something like this for a search term: 64111 lamp
There are many possible other lamp substitutions possible for various places on the motorcycle. I have information available on many lamp numbers.
The actual drain and power/light output of a lamp depends on the ACTUAL measured voltage at the lamp itself.
Part 5: ....more on wiring, lamp life, etc:
Increasing the wire gauge size to the headlight, and/or using a heavy duty relay (a relay is VASTLY better at this, and eliminates all high currents at the hi/low stock switch), can brighten your headlight by reducing voltage losses. The stock headlight (except early /5 which had 40/45 watts) is 55/60 watts and the bars switch in particular will NOT hold up to larger lamps (80 watts probably for awhile, but not 100+) that one might put in the headlight shell....or for added headlamps; and, hence a heavy duty 20 or 30 ampere relay from a local auto-parts store, is relatively INexpensive and OK. NOTE!...use of a headlight modulator with an INcreased lamp wattage size also means you should use a relay.
Versatile relays that can work fine for most functions in your motorcycle, such as switching lamps, running horns, starting, etc., is the Bosch (now Tyco) 330-073, rated at 30/40 amperes and 12 volts, SPDT, 5 pin, with tab for screw (tab area can be removed); or the Blazer DF005 or DF005W which also has a tab/screw mounting.
There are OTHER considerations:
There are some things not usually discussed about changing the
wiring, adding relays, ETC., ....besides the need to do it neatly
so that the bike can not burn up. On THAT
subject, one must avoid poor connections, bare wiring, places
rubbing could compromise the
insulation, and, of
course, have a FUSE!
IN almost every instance of adding one
or two relays; you will want a
direct to battery connection via a fuse. Did you know that BMW does not generally fuse the headlamp circuit?
BMW could have used larger gauge wires for the lighting, and elected not to, and had some safety reasons for what they did. I hope the following will discuss more factors and that I have not forgotten anything:
The light output of a lamp is increased only a very small amount for a 5% increase in voltage, and that is probably the improvement you might make at the headlight with a directly connected larger gauge wire, fuse, switch....or using heavy wiring and a heavy duty relay. BUT the LIFE of the lamp is probably decreased, out of proportion to the smaller percentage increase in light. This is a general property of
incandescent lights, including halogen types (which are a bit less affected). Not only is the life decreased from the lamp life otherwise obtained, but the lamp may get a slightly higher voltage AT turn-on, and the slightly higher inrush current on a cold lamp may decrease life even more. Typically, in an airhead, with reasonably decent wiring, switch contacts, etc., the headlight will see about 0.5 to 0.8 volt less than the battery terminals will show. This is a wee bit less voltage, a couple or few tenths or so, than the voltage shown on the fairing voltmeter, if you have one of those and it is accurate (usually they are accurate for the point at which they are connected, which is NOT the battery). Those voltmeters usually show 0.3 volt lower than a direct battery terminal measurement.
Lamps used in vehicles are not all rated at 12 volts. Some are rated at 12.8, or 14.0. Some foreign, German too, lamps ARE rated at 12 volts nominally, but the WAY they are rated and tested amounts to about the same thing as U.S. lamps, in effect, so I will treat them the same, although they ARE differently rated. Yes, I know that the Europeans and the U.S., has used slightly different voltages on some, at
times...but the principal here holds up. The 14.0 volt rating is typically used for lamps that are ON all the time the engine is running. The headlight is a special case though, and is not thusly rated. The 12.8 rating is generally for higher drain lamps that are used only for short periods, such as turn signals and brake lights. These lamps usually have a much higher rated wattage than other small lamps, such as clearance and running lamps and dash lights, and hence will put more of a load on the system, and typically the engine is idling, or soon will be, or producing little electricity from the alternator, and the manufacturer's KNOW that the voltage AT THE LAMPS will thus be quickly reasonably close to that 12.8, and hence that is the rated voltage. I suspect that the lamps are overpowered on purpose, so are brighter. A case could be made by nerdy engineer-types about the faster lighting-up, or the transient period from high system voltage to the decreased voltage...but I won't get into that here. The headlamp is a special case, and has complicated ratings, not easily found in specification books.
When you raise the system voltage, whether by an alternator conversion that increases the voltage at idle and certainly above, and/or, by higher voltage regulator settings, larger gauge wires, relays, etc.....you can expect shorter lamp life. That is the tradeoff. There is another, more minor tradeoff, in that the DRAIN in watts will also be a bit higher. You may find that all the special wiring and relays, for the stock lamp, don't make a lot of difference. You can find out how much difference light output MIGHT be, by turning on the headlight, and then ADDING, temporarily, and momentarily, a heavy duty (large gauge, perhaps #16) wire from the battery + terminal directly to the energized headlight terminal. Do this at idle rpm, and also do it with the system at an rpm (and battery fully charged) that has the maximum system voltage. You will see the difference.
If your bike has larger voltage drops, you probably need to attend to the various connections, plugs, sockets, even relays and ignition switch, etc. One of the worst places for problems is the larger gauge red wire connections at the starter relay, and at a slightly loose starter motor solenoid terminal nut that the large gauge battery wire connects to. Other places often having problems are the connections at the diode board.
Those who are running heated clothing during the daytime, and are running at or near the limits of alternator output, and do not wish to spend the $$$ for the alternator conversion, can consider a headlight modulator, which will save quite a few watts (in effect)....besides adding to your safety (and annoying oncoming drivers, or them if in front of you...SOME will undoubtedly say). Those with a lot of additional
headlight power and/or heated clothing SHOULD have the larger aftermarket alternators.
Part 6: HEADLIGHT MODULATORS, in depth, and recommendations:
NOTE!!!!....I have an article on this website with the federal law allowing modulators, and the technical details.
Headlight modulators; the Federal Law authorizing them; the technical details
That is a clickable hyperlink
I LIKE Headlight Modulators. I always have mine ON during the daytime, which means I have a blinking Hi Beam. Others hate them, feel they annoy folks. Frankly, the purpose is not to annoy, but to attract attention, and they seem to do that fairly well, although in really bright sunlight your headlight is perhaps not easy to see from an oncoming car driver's standpoint. But, that is true for any headlight,
modulator or not. I think they are just one more safety item. One of my nicknames, from a Club I ride with now and then, is BLINKY...due to my modulators. I had a custom high power modulator on my sidecar tug (1983 R100RT), had it for maybe 19 years. It was massive, will power an aircraft landing light (don't ask!). Prior to that bike, there was a home-made modulator on one of my R75/5 bikes. I had a
Kisan unit on my solo bike (1984 R100RT), and I also put a Kisan modulator into Lilli's R80ST as a little gift, and I have a Kisan modulator on my K1100LT-EML sidecar rig. The Kisan unit is available from quite a few motorcycle dealers, and they are not cheap, retail is around $100.00, but they are really trick, neat units. I've installed dozens of them. They are programmable, neat-O, and fairly reliable. Mount the photocell unit cleverly. Ask me, if you have questions on that.
Decades ago, modulators were of all sorts of types and
usages. Now, the frequency, duration, etc., of the
headlight period on versus off is
specified in Federal Law.
Also specified is the use on only the high beam.
Oversimplified here, but close enough. Because of the
and Federal money into the States' road systems,
headlight modulators for motorcycles are approved in every
State. Some States have their
own laws, but I don't know of
any that negate the federal requirements, I suppose that is
possible on non-federal roads, but have heard of
no problems. So, for practical matters, they are legal
everyplace in the USA. If you want to make your own modulator,
some schematics are on
website. One version will modulate either beam, as it is
inserted into the stock headlamp ground circuit.
A CLEVER headlight modulator comes from the company called KISAN (KisanTech). These are simple to install, since they are a wafer affair that simply plugs into the rear of the headlamp bulb, then you plug in the regular cable. There is NO wiring to connect to power or ground, etc. The Kisan unit has another cable, that is thin and long enough, it plugs into the wafer unit on some models, and the other end of the cable is the photocell, a Federal requirement. The unit automatically works on only the high beam because of how the plug is made; and, will not operate at night due to the photocell. The photocell has three sensitivities and you program the unit, if you have to (usually not), by simply turning the ignition key rapidly on and off per the booklet that comes with every unit. It is very easy to install. I like the design, obviously, since I have installed dozens. I also can recommend another type, from EasternBeaver.com. That company sells a relay kit that is nearly plug and play...easy installation, and fused too.
Because there are several types of headlight bulbs used on motorcycles, one has to get the proper Kisan model. They handle up to a 100 watt lamp. In operation, you still have the various stock functions of your bar switches.
Due to a peculiarity of the halogen H4 headlight bulb, your headlight, on the high beam at least, will probably last LONGER, generally, with the modulator. NOTE!....Light output is improved with a headlight modulator only by using a heavy duty relay. You don't HAVE TO do that, however, as the light output increase is rather small or modest. HOWEVER, if you are using a high wattage lamp (over 70 watts), then it is a must to install a relay, to protect the bars switch. You can do this with one or two Bosch relays yourself, or just buy EasternBeaver's modulator with relays. If just wanting relays on the stock headlight, they also have a nice relay package.
(1) A modulator can be made in two standards ways. In one method, the modulator is turned on, then fully off, at a roughly 4 Hertz rate. In another method, the Federal law specifies this, the modulator does not fully turn off during the flashing mode. Many a modulator does not conform, and has no need to, since the visual effect is about the same!...this is due to the inertia of the filament of the lamp. On a practical basis it makes NO difference about turn-on and turn-off, as the rate of flashing is fast enough, and equal enough in time between on and less on or off periods, that the bulb filament never 100% cools off. The law was wishy-washy on how it was worded...does headlight power mean electric or light output?
(2) The flashing mode is officially, by law, set at 4 Hz to annoy (become more recognized...) the brain alpha rhythms...or some such.
(3) ONE OTHER good thing comes from
the use of a modulator. Since the period of time the
modulator is ON is changed, the
EFFECTIVE use of WATTS from
your charging system is REDUCED (call it average watts if you want to). I have not made a
quantitative study of this, but you should
gain 20 to 30 watts effectively. There is also a VERY SMALL voltage drop in the
unit, but it has only a FAINT effect on light output and
I happen to like things
that add to safety, and I THINK these modulators DO, very considerably. The
lamps last longer; and,
you get some additional watts from the
alternator on high beam
NOTE that Jim at http://www.Easternbeaver.com has a lot of interesting goodies, including relays for when you use higher powered lamps or just want more solid voltage to your headlight. LOTS of good wiring things on that site, and Jim is a good guy to boot. He has a very clever combination modulator and relays setup, almost plug and play, that does it all for you.
I prefer, however, and ESPECIALLY with MUCH higher power lamps, to use one or two separate relays, of the 20 or 30 ampere autoparts store type.
Part 7: Resources, etc.:
The above URL's has a lot of lamp information,
but I do not agree with some minor portions of them;..for
instance the inference that
DC and AC life is not all that
different....other places here....but GOOD stuff otherwise.
NOTE! For those installing extra lamps, or have specific reasons to replace an existing flasher unit,....ETC.....there is a heavy duty flasher unit available at auto-parts stores, under the SignalStat brand, model 263. Mechanical and electrical. Flash rate is 60 to 120 per minute, has 3 each 1/4" male spades, is 1.33" round, 1.35" high, works on 11-15 volts, and from well below freezing to damned hot. It will handle 20 ampere loads!! It is a very good idea to know what you are doing when installing a substitute flasher!
Versatile relays that can work fine for most functions in your motorcycle, such as switching lamps, running horns, starting, etc., is the Bosch (now Tyco) 330-073, rated at 30/40 amperes and 12 volts, SPDT, 5 pin, with tab for screw (tab area can be removed); or the Blazer DF005 or DF005W which also has a tab/screw mounting.
to 02/03/2003: clarifications:
headlamp shell, use of 9003 in /5; minor additions to
headlamp and eyebrow lamps usage and add socket and harness numbers.
04/17/2003: add .htm title; clarifications here and there.
07/13/2003: /5 large alternator information clarified; add 2825, 2821, and some notes on these types;
09/15/2003: lots of clarifications and includes LED indicators information, more links.
11/22/2003: Clarify 20 watt lamp and part numbers
01/03/2004: revise in several places for clarity, add section on wire gauges, relays, and in-depth lamp life
considerations. Add -24 ID to top of article
04/03/2004 : Greatly expand section on side headlight shell information; also add #64198 for /5; edit
entire article a bit.
08/25/2004: minor updates, comments on 2825
10/29/2004: add part 3.
07/05/2005: lamp information updated for 64115
03/23/2006: slight updating
03/25/2006: more lamp substitutions for BMW -279.
03/26/2006: final extensive editing
02/07/2007: minor editing, mostly for clarity
01/08/2008: fix URL's; add Eastern Beaver information; and revise the modulator section
06/26/2008: add Osram 64205 information
11/03/2008: add more information on PIAA and other headlamp bulbs
06/21/2009: Recheck article. Minor clarity improvements
07/13/2009: Add hyperlink to article with the federal modulators law
08/28/2009: Add paragraph in two places on lamp sockets and their numbers.
09/15/2009: add a bit more information on the 64205 and 64206 lamps....and later in the day, add more
information on high temperature sockets for H4 lamps....and, more, on 09/16/2009.
10/21/2009: Add sketch of H4 lamp base and revise article for more clarity.
12/05/2009: Add Signal Stat information
02/18/2010: clear up wrong or misleading information on the 4 watt lamps; and add the -576 later part
04/20/2010: remove mbz hyperlink
11/17/2010: Clean up article of typos, extended line lengths in certain places, clarity, etc.
05/09/2011: Add information on Eastern Beaver's ceramic sockets
07/04/2011: Add K bike rear run and brake lamp information
05/13/2012: Add information on headlight specific lumens @ specific voltages, update other areas (minor)
06/08/2012: Expand the section on 1156, 1157, 7506, 7528 lamps, to explain the confusion as best I can.
09/18/2012: Fix typo on 7528 lamps (in one place was listed as 7527) and expand the alternator voltage
and current on that 7528, as not all manufacturer's rate it at the same voltage.
Add QR code and update Google code
01/07/2013: Add more information on voltage, life, Euro versus USA, and explanations.
05/16/2013: Review and update article.
© Copyright, 2013, R. Fleischer
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