INSTALLING AN ACCESSORY ELECTRICAL OUTLET
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accessoryoutlet.htm-27

There is nothing very complicated about installing the standard accessory outlet (socket) (jack) onto almost any airhead. The female socket and male plugs are available from many sources ...and various styles of these sockets are available.   

An accessory jack should have, or you should incorporate, a FUSE in the POSITIVE (+) lead (usually red, and is the lead that goes to the CENTER jack contact, the STOCK fuse size was 8 amperes), and be wired directly to the battery + terminal, unless you have a REALLY GOOD reason to wire it through the ignition switch. I suggest wiring directly via a fuse to the battery, thereby avoiding having to have the ignition switch on...and....the accessory socket (jack) is a great place to plug in your battery charger, and thereby avoid problems with alligator clips, sparks, etc. You wouldn't want the key ON, during battery charging! Use appropriate gauge and insulation wire type, and put the fuseholder in a convenient place.

***SEE later in this posting about the negative wire!!

Have the jack located where you won't have excessive wire lengths....or other problems such as pulling on your clothing;....when you plug in your heated clothing and mount and dismount the bike.    Some folks will have two or even three of these accessory sockets, some have one direct to the battery and others through the ignition switch.

For the RIDER who happens to have an appropriate fairing, consider the rear of the fairing left pocket, if it has one;....as MOST heated vests have the VEST connection on the left side, AFAIK.  If you put the jack in such a place, be SURE nothing put into the compartment can cause a short circuit.  Shrink tubing or other good insulation is usually a good idea.  Black electrical tape is not a good idea...it tends to unravel over a long time period, besides often making a sticky mess after some time.

If you have a fairing, and a passenger along that wants heated clothing, probably at least two separate jacks is best, with the passenger's being in the stock area that BMW provided...at the seat lock area on the left side (obviously this does not apply to those with rear seat locks such as a ST model).   Some folks install three of these jacks, and run all sorts of electrical devices from them.

The stock position for many BMW airheads was at the left side seat lock area and BMW had a thick sheet metal bracket just for the plug. See any BMW with one of these, they were standard on many models (especially RT). 

The part number for the jack has been changed now and then, for example it was 61-13-1-243-661, now is 61-13-1-379-719; and the folding weather protecting cover for it was 61-12-1-243-662, which became 61-12-2-393-574. Better check those numbers, may be wrong by now.   Old style jacks used either no cover, or a rubber cover, and some versions of the jacks have a plastic flexi cover, that will eventually break.....the better type, K models, had a hard cover, spring loaded.   Be very careful you get the type you want, and that is reasonably weatherproof.  There are flat jack assemblies on the aftermarket, so the plug goes in without sticking outward.

For models like the R65 the fuse box is on the right side of the frame and could be modified for an extra jack.,,,,perhaps not so convenient for clothing.  That fuse box...on rear of the box...might be a convenient place to mount a heated clothing thermostat. 

Be cautious. You do NOT want any wire, connecting to the jack from your clothing, becoming disconnected....and flying into your rear wheel!

I suggest not fastening the jack to the handlebars, due to possible constant wire movement problems, and perhaps safety problems. Could be done properly, of course, and BMW included such on some models, like some of the K bikes.

One CAN make a bracket, or maybe purchase one, and mount a standard cigarette lighter jack someplace similar. Most of these jacks have a somewhat flimsy outer metal shell that acts as the 'nut' and must be installed securely and electrically correct for grounding. I do not like them for their poor grounding, and that the center contact is fairly poor, compared to the type of gripping contact for the stock BMW plug and socket.  Some of these cigarette jack shells do have a grounding spade tab.

Whatever you do, do it neatly, fuse the positive lead, and install the wires and fuses such that they won't short circuit or fray from vibration.  If the wires are substantial in size, you could go as high as 30 amperes, which is about the limit for the jack and plug.  Don't willy-nilly go to large fuse sizes if you have no REAL need.  Don't try to have high current capability if you wire this through the ignition switch, that switch is not rated for much more than it carries already.

***ONE special precaution:
When you attach an accessory socket...or anything electrical really...to your airhead... you may or may not be contemplating the connection of its grounding or negative wire to the ACTUAL battery negative POST. I feel that it is BETTER, over-all, to NOT connect this accessory jack...radio....or whatever....directly to the battery negative post. While electrically it may be a tiny bit better under SOME situations, a problem can come up, so I am advising NO direct connections to the battery negative post. 
Here is the reasoning:
It is STANDARD practice on a BMW airhead to electrically disconnect the battery, when you need to do such as remove the outer timing chest cover; by removing the battery heavy negative black wire from the transmission speedometer cable hollow vent bolt. This thin hollow bolt is located at the right rear of the transmission.  That bolt has a triple function; it grounds the battery to the engine, it vents the driveshaft and transmission, it secures the speedometer cable.   Thus, if you have something connected directly to the battery negative terminal
that is, in itself, grounded, such as the shell of an accessory jack (some shells or outer parts are grounded by the mounting)...you are defeating the purpose of disconnecting the large gauge battery wire at that hollow vent bolt....and can seriously damage your diode board, as one example, upon removing the front cover.  By grounding your accessory jack to the FRAME, not the battery negative terminal, you avoid problems.  
With SOME accessory sockets (yes, even some of the DIN German type), the shell is insulated; with others the negative is part of a metal shell, and if it is mounted in the plastic of the fairing, there MAY be no problem. So, no matter what the situation, and they vary, be sure that the negative connection is to the frame, not the battery negative post, UNLESS you KNOW what you are doing! 

When I post something to the Airheads E-mail LIST about electrical work you may read that I said to remove all wires at the battery NEGATIVE "POST"...this ASSURES no ground paths, no matter WHAT someone did with wiring.  It is a safety precaution for me to say it that way.

So, I suggest you not add things to the battery negative post, and instead find another nice grounding point for your accessory jack. Look for most anyplace on the bike that has a screw or bolt to the frame, and/or maybe one or more brown wires connected at that point.


HINT: It is convenient to cut a SMALL slice out of the battery lug located at that speedometer cable point...so the vent screw only needs slight loosening.   Be sure your hollow bolt has the washers on it, which will prevent spreading of the lug.  The battery lug goes between the washers.

 

revisions:
11/14/2008:  incorporate all prior revisions, and update for clarity

 

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