Lamps

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lamps.htm-24A

This article covers lamp theory,  lamp substitutions, updating the /5 headlight, adding relays, fuses, large headlights, heavier gauge wiring,  and HEADLIGHT MODULATORS.

It does not, yet, cover LED lamp substitutions, although I discuss them, SOMEwhat.

 

Please refer to article(s) on the Airheads Club website; which will have more to say about specific relays, etc.  The URL is:   http://www.airheads.org   Click on that main page for Technical Tips articles.

 

PLEASE see article 24B, that discusses the headlight relay, the internal diode, 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:

BMW stock lamps are arguably perhaps the best for your bike; except for the non-halogen early /5 headlight lamp & lens/reflector assembly, which is vastly improved by upgrading the lamp, lens, and reflector, by the original conversion kit parts or, cheaper perhaps, from an R65....or using a special 64198 lamp.

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.

 ***The early unconverted /5, that is, stock, used a 40/45 watt headlamp, and it was NOT a halogen lamp.  It is possible to obtain a H4 in higher power that fits the /5 socket.  That is GENERALLY not a great idea with the original lens and reflector, as the light pattern will be so-so, an effect of the glass lens...and the reflector...but SOME folks may like it.   Better to use the Kit BMW offered for this; or, the reflector and lens of a R65 will adapt at less cost.   The stock 180 watt /5 alternator is adequate.  It is possible to update the alternator to the larger size(s) 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 year.   However, a high powered alternator to fit all airheads, including the /5, is available, it is called the EnDuraLast....available in 105 mm size for the /5, and 107 mm for later models.

 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.   

NOTE:  German or other foreign auto-parts stores might carry the 60/55 watt halogen lamp type #64198, an Osram number, which has a  filament arrangement that will work OK with the stock /5 reflector and lens.  see below

The BMW 55/60 watt halogen H4 headlight lamp (similar to common type 9003 and really same as BP1260-H4)  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 Bosch 20 or 30 ampere types are not expensive and are fine for this), using the original light switch output for the relay coil. You can do this conversion with ONE relay, if that relay is "SPDT", which means Single Pole Double Throw.  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.  The second section of this article has more to say on this matter.    #9003 lamps work fine for stock usage...and there are many variations, some of which throw better light patterns.    The Eastern Beaver company makes nifty relay kits, that PLUG IN!

The best lamp I have found, to be used with stock OR relays, is the Osram lamp 64205, it is rated at 70/65.  It has a very nice output, and at 2000/1350 lumens too.

 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 misleading.

****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.

****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 then flushed with clear water. Allow to dry VERY thoroughly before installing the lamp, etc.  I do not try to separate the glass part, I do my cleaning through the lamp hole.

Roy Truelsen, once a Member of the Airheads LIST,  posted information to the Airheads Mailing LIST about using larger, more powerful lamps, particularly for the instruments/pod. His articles are probably still in the Archives and probably still on the Club's .org website.   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 such larger lamps that have SO MUCH extra heat, that 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. 

Part II

LED's:

NOTE that very bright white LED lamps that fit the indicator sockets on some pod models are now available reasonably priced.  However, some give insufficient light output, some are not 12 volt rated, and most do not mount in the original sockets....some that do are now available.

  Note also that LED lamps do not always project much light to the sides and also that they do not work in flasher circuits in which the flasher unit is load dependent, without additional changes.  BMW has used a number of different flasher circuits on our Airheads...for some, the LED 12 volt lamps, or ones with added resistors work just fine.   Many types of LED's and multiple LED lamp assemblies are available commercially.  BE cautious about their use, especially for the rear tail light.   

Modifying to LED 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 either.   It is true that a LED lamp usually lasts almost forever, if properly powered.  It may, however, be hard to see, especially in the daytime.

 

PART III:

***NOTE that if your bike has one stock rear running lamp, and it fails, you have NO light to the rear...at all.   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.  It is actually possible to defeat that, but is complicated.

When a common lamp fails it is almost always because the filament broke from being thinned, or stretched/sagged, or all these things, over a long period of time. You can generally identify a lamp that is thinking about dying, as the filament is visibly sagging. This is particularly noticeable in the turn signal and taillight lamps. Thus, regularly, you should visually inspect the lamps.  This is highly recommended for the rear running and brake light(s).  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.  NOTE that when the turn signals are flashing on and off, that type of on-off usage detracts greatly from their official life expectancy.    

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 rated for DC.    

 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.   Use of proper types of HEADLIGHT modulators are legal in all States, and is codified into Federal Law for motorcycles.   

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 light output. 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.  Life is vastly shorter if a AC rated lamp is used on DC.

BUT...notice!!:   life INcreases GENERALLY at the 12th (some books say 8th) POWER of the INcrease in the voltage rating 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.    Thus, over-voltage applications 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 voltmeter read 13.7, and the brake light when illuminated be actually at 13.2 volts.   This has an effect on lamp life, referring to the RATED voltage of the lamp...which is likely 12.8 for the BRAKE lamp filament.   

 To restate this a bit clearer, 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, and vice versa!  NOTE that whilst life of normal NON-halogen lamps increases, continually, as voltage is dropped, not so the halogen....which, if 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 effect for our bikes.

DC (direct current...battery power) operation of lamps REDUCES lamp life. 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 hardly have AC systems driving the lamps. There are some exceptions.  My old Vespa had both a DC output for the battery, coil ignition, and tailight, 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, at RATED lamp voltage.  

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 reduces 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, 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. 

ONE more way to think about this:  If your voltage regulator is set for 14.9 volts (the upper limit for a Panasonic type of battery), you might expect less life on your lamps.  They will be somewhat brighter though.  Probably 14.3 is a nice value for most batteries as a compromise.   Certainly, the 13.8 that is often found will extend lamp life considerably.   You can expect your BRAKE and TURN lamps to have REDUCED life with over 14 volts.

A lamp with 50%-100% greater instrument-measured (or specified) light output will NOT look all that much brighter to your eye. 

PART IV:
Lamp equivalents and/or substitutions:

Various lamps in the airhead can be substituted WITHOUT problems.  Many folks know that 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. There are substitutes for EVERY lamp. Some are OK, some perhaps not. 

The Alternator lamp 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 stops the alternator from ANY output.   The article is the genlampresistor.htm article.


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, 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 also 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 more performance by using the latest 2.8 ohm rotor, if your rotor is an earlier version.     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 lamps #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.
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 200 hours.
 (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.

Turn signal and brake lamps:  12 volt, 21 watt #07-11-9-978-370, substitute is common #1156. The 1156 lamp is rated 12 volts, 2.1 ampere, 27 watts, 1200 hours (a.c.)....which is a BIT brighter...you probably won't notice.

For those who have converted their turn signals to be turn and run lamps, the usually used lamp is a double contact lamp, common #1157.  That lamp has two sections, one is far brighter (TURN) than the other. The sections are: 12.8 volts, 2.1 ampere, 27 watts, 1200 hours (a.c.); and, 14.0 volts, .59 ampere, 8.26 watts, 5000 hours (a.c.).  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, of course.  But, that is normal for any highly stressed turn and brake lamps, stock or not.

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.

***In a few instances, such as some brake light (stop light) bulbs, the bulb is rated at 12.8 volts. It is possible for more than that voltage to be on that bulb in actual use, further decreasing life, but typically not too much more, as there are voltage drops in the wiring and connections.   What happens is that the brake lamp drain is high enough such that the system voltage drops somewhat, much more so by the time you are stopped, engine is at idle rpm.  Still, do NOT expect long life from turn and brake lamps.

The normally 4 watt parking lamp 07-11-9-978-256 when used in SOME models in the headlamp REFLECTOR SHELL (on the faired RS/RT models no lamp was fitted, but CAN BE), can be fitted with substitutions, and also vastly brighter lamps.    Some might want weak lamps, such as the #1893.  There are a lot of these types of  "standard miniature bayonet" lamps, such as 1889, 1895, 1891, 57 (round lamp on the 57and 1895).    Some folks do this for 'daytime running'.   Some folks have a headlight on/off switch, and use this lamp to save watts, a 5 watt halogen used here is considerably brighter, and a 10 or 20 watt halogen is quite 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 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 for a daytime headlight function.   The eyebrow lamp housing 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.
FYI:  Stock 4 watt:  BMW 07-11-9-978-256.
Small radio lamps:  The 1893 is similar to the original 4 watt; other numbers usable are 1891, 1895, 1889.

 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 of 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, and prices vary 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.

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Part IV....more on wiring, lamp life, etc:


Increasing the wire gauge size to the headlight, and/or using a heavy duty relay and switch, can brighten your headlight by reducing voltage losses.  The stock headlight (except early /5)  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 (Bosch types, black, in plastic cases, local autoparts stores, are relatively INexpensive and OK).   
NOTE!...use of a headlight modulator with an INcreased lamp wattage size also means you should use a relay.

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 and foolproof, 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.
    BMW could have used larger gauge wires for the lighting, and elected not to, and had some reasons for what they did.    I hope the following will discuss all the 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 GREATLY decreased, way out of proportion to the vastly smaller percentage increase in light.  This is a general property of incandescent lights, including halogen types.   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 a tad more.  Typically, in an airhead, with reasonably decent wiring, switch contacts, etc., the headlight will see about half a volt less than the battery, sometimes a bit more.  This is a wee bit less voltage, a couple 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).    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 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 producing little electricity from the alternator, and the manufacturer's KNOW that the voltage AT THE LAMPS will thus be reasonably close to that 12.8, and hence that is the rated voltage.   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 or a bit 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 it MIGHT make, if things you contemplate doing were near perfect, by turning on the headlight, and then ADDING, temporarily, a heavy duty wire from the battery + terminal directly to the energized headlight terminal.  Do this at idle rpm, and do it with the system at an rpm (and battery fully charged) that has the maximum system voltage.
    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.  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, SOME will undoubtedly say).   Those with an additional headlight and heated clothing MUST have larger alternators.  

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Part V:  

HEADLIGHT MODULATORS, in depth, and recommendations:


 I am a big fan of Headlight Modulators.  I always have mine ON during the daytime, which means I have a blinking Hi Beam, since that is what I leave on.   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 extra safety item.    One of my nicknames, from a Club I ride with now and then, is BLINKY...due to my modulators.  I have (HAD, it is sold) 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 my R75/5.  I presently have a Kisan unit on my solo bike (1984 R100RT), and put a Kisan modulator into Lilli's R80ST as a little gift, and 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 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.  NOWadays, 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 Federal law, 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 nothing like that.  So, for practical matters, they are legal everyplace.   If you want to make your own modulator, some schematics are on the www.ibmwr.org 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 requirement.   The unit automatically works on only the high beam because of how it's 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 key rapidly on and off per the booklet that comes with every unit.   It is very easy to install, usually without drilling any holes anyplace, or just one small one.   I like the design, obviously, since I have installed dozens.  I recommend another type, from EasternBeaver.com, below.
     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 left 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, than without the modulator.  NOTE!....Light output is improved with a headlight modulator 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 60 watts), then it is a must.  You can do this with one or two Bosch relays yourself, or just buy EasternBeaver's modulator with relays.  Frankly, I have NOT found it necessary to use headlight relays UNLESS the lamp is OVER the stock 55/60 watt....then relays are mandatory anyway to protect the switch on the bars.


     Somewhat technical:......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 Federals specify this, the modulator does not fully turn off during the flashing mode. The flashing mode is set at 4 Hz to annoy (become more recognized...) the brain alpha rhythms...or some such.   On a practical basis it makes NO difference about turn-on, 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?     ONE OTHER good thing comes from the use of a modulator.  Since the period of time the modulator is ON is not constant, the EFFECTIVE use of WATTS from your charging system is REDUCED.   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 drain.  I am sure to get hate mail over this, but I happen to like things that add to safety, and I THINK these things DO.  And the lamps last longer, and you get some additional watts from the alternator on high beam daytime use.
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 this 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.



Resources:

http://members.misty.com/don/

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.

http://lighting.mbz.org/tech/tech.html
This is the URL for extensive information on lighting, which will dispel a lot of wrong information on lamps...it is a very extensive data and information base, covering MUCH that is not here on the page you are reading.   Plan on spending some time browsing.

Revisions:

to 02/03/2003: clarifications:  headlamp shell, use of 9003 in /5; minor additions to descriptions; 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; resources URL's. 
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

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