Snowbum's BMW Motorcycle Repair & Information Website

For the rider who has a 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.  If you put the jack in such a place, be SURE nothing is put into the compartment that can cause a short circuit.  Shrink tubing or other good insulation is usually a good idea.  Black electrical tape or worse yet, duct tape ....are not good ideas ....they tend to unravel over a long time period, besides eventually making a sticky mess.

If you have a fairing & a passenger that also wants heated clothing, probably at least two separate outlets is better, with the passenger outlet being in the stock outlet area that BMW usually provided.   Some folks install three of these jacks & run all sorts of electrical devices from them.  The stock position for the standard accessories jack on many BMW Airheads was at the left side seat lock area & BMW had a special thick sheet metal bracket just for this outlet.  See any BMW with one of these, they were standard on many models (especially RT).  The part number for the socket, often called a jack, has been changed now & then.  For example, it was 61 13 1 243 661, then 61 13 1 379 719; & 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 sockets used either no cover, or a rubber cover, & some versions of them 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 & that it is reasonably weatherproof.  There are 90° PLUG assemblies on the aftermarket, so the plug goes into the socket without sticking out very far.  For models like the R65, the fuse box is on the right side of the frame & could be modified for an extra socket, but 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 carefull. You do NOT want any wire, connecting to the outlet from your clothing, becoming disconnected ....& fly into your rear wheel, bang your paint, or anything else!

I suggest not fastening the socket to the handlebars, due to possible constant wire movement problems, & perhaps safety problems. Could be done properly of course, & BMW included such on some models, like the K-LT & other bikes where BMW installed a jack on the bars trim piece.  BMW also usually installed one or two other jacks near the ignition coils on those K-LT models. Thus, those K models came with 3 outlets/inlets.

One CAN make a bracket, or maybe purchase one, & mount a standard cigarette lighter jack someplace similar. Most  'cigarette' jacks have a somewhat flimsy outer metal shell that acts as the 'nut' & must be installed securely & electrically solidly correct for grounding. I do not like them at all because of their poor grounding, poor friction with the plug, & that the center contact is fairly poor, compared to the type of gripping contact (DIN plug, DIN jack, Hella plug or jack) for the stock BMW plug and socket.  Some of these cigarette jack shells do have a grounding spade tab, ....but mostly that ground tab is from the shell which acts as the nut; but those with the tab from the inner piece are much better.   There can be a problem with the shell always contacting ground.  I get into this a couple of paragraphs further down.

Whatever you do, do it neatly, fuse the positive lead, & if you install in-line fuses, install any fuse such that it will not 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 absolute limit for a jack & 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.   Relays are mostly not used to due contacts problems for accessory sockets.

***A special precaution:
When you attach an accessory socket ...or anything electrical ...to your Airhead (this can apply to many other bikes too)... you may be planning to make the connection of the grounding (- wire) to the ACTUAL battery negative POST.  It is BETTER to NOT connect an accessory jack ...or radio ....etc.  ....directly to the battery negative post. While electrically it may be a TEENY bit better under SOME situations, a problem can arise, so I am advising NO direct connections to the battery negative post ....and ....the reasons follow:

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.  The normal method to disconnect the battery is to remove 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 & transmission, & it secures the speedometer cable. 
The PROBLEM occurs this way:  If you have something connected directly to the battery negative terminal such as the shell of an electrical outlet socket; and some shells or outer parts are grounded by their mounting...then you are defeating the purpose of disconnecting the large gauge battery wire at that hollow vent bolt (or, other place someone may have connected it to, such as the frame or transmission).  You can seriously damage your diode board, as one example, upon removing the front cover.  You may be leaving the system powered, while you think it is not, & there can be real nasty expensive problems.

By grounding your accessory outlet(s) to the FRAME someplace, & NOT the battery negative post/terminal, you avoid such problems.  with SOME accessory sockets (yes, even some of the DIN German types), the shell is insulated; with others the negative is part of a metal shell, & if it is mounted in the plastic of the fairing, there might be no problem.  No matter what the situation, & that varies, I usually suggest you make all accessory (-) connections to the frame, not the battery negative post, UNLESS you KNOW what you are doing & WANT it that way!  To restate my advice:  the accessory socket should NOT be grounded at the battery negative post.

When I post something on the internet on a forum, List, etc. about electrical work, you may read that I say something like:  "Remove all wires at the battery NEGATIVE POST".  This ASSURES no ground paths, no matter WHAT someone did with the wiring.  It is a safety precaution for me to say it that way, & in line with the above paragraphs now you know why.