Vintage BMW Motorcycle Owners

That switch is surprisingly delicate when compare to the rest to the motorcycle.
Twenty years ago I opened mine up while debugging a lighting problem. All I remember is something was broken in the switch, I used a piece of inner tube to keep everything in place, and vowed to never remove it again. Back then I couldn't locate a replacement. Oh, and the problem wasn't the switch, it was a loose wire in the headlight.

Don

Still haven't sorted out my switch issue on my R60. I've got brake light and horn working (mostly, sounds like needs contacts cleaning), but no headlight or tailight. Bulbs check out good. Ignition switch doesn't seem to have any "slop" in it-- nice positive connection and movement with the key.

The lights did work when I got the bike, and failed at the same time-- as I recall when the horn button was pushed. The wiring in the bucket looks like a dogs breakfast and doesn't seem to match up to the wiring diagram. HO on the ignition board had no wires or screw in it (I'll need to find a replacement screw)! I've rectified that for now using the wiring diagram...but still no head/taillight.

I'm getting continuity between the handlebars and the headlight socket wiring. That seems odd to me, like the switch is grounding on the bars. I've got a multitester, although I'm no genius at using it-- or at bike electrics in general-- so have run out of ideas.

The switch seems like a very delicate, Rube Goldberg type of thing, and as Don-- and Duane, elsewhere-- has said, it is tricky to work on. So before I try to tear this thing apart or replace it (ouch, stupidly pricey), anyone got any ideas? Thanks!

Got the switch out today and checked the wiring-- all the wires are going to the correct places as per the wiring diagram, and the advice here.

What's odd though is that when I check for continuity on each of the wires in the switch to the bucket, I not only get continuity to the corresponding wire and junction in the headlight, but I also get continuity to every other wire in the headlight coming from the switch, as well as the handlebars, etc. Now maybe I'm using my multimeter wrong, but I've used one for years...and am puzzled. Does that mean my switch is shorted/fried? To be honest, it doesn't look that old or in bad shape, and seems to be wired up correctly.

Baffled. Thanks in advance for any ideas. As I say, this worked fine until one day when I pushed the horn button and it all stopped working, except the horn (a little bit) and the brake light.

That will happen because the bulbs have continuity to ground. Remember #56 is KEY. That is the main + power to the handlebar headlight switch. The switch sends switched + to high or low beam. I had a problem recently where I had only my parking light working and no headlights. It was a combination of high resistance in the wiring harness. DO NOT take out the circuit board!! It is very simple and probably NOT the problem. Start off simple,check your terminal connections at your battery,then the ground and power connection at regulator then connections from regulator to headlight bucket. 90% of electrical problems are poor/corroded connections!

I took this pictures some time ago.

Many thanks, Thomas and San Arthur...I'll check all that out.

Currently, with the key down, I've got functioning brake light and horn, as well as a lit-up charging and neutral light. The battery shows 6.25 volts. The ground at the battery tests good. The bulbs work if I apply power directly from the battery. I have continuity between the switch terminals and their headlight counterparts. But I am still lacking any headlight and any twilight (other than brake light when the pedal is depressed).

Not sure if any of that makes a difference but I'll keep checking connections as you suggest. I agree that the headlight board seems unlikely, both because it seems relatively new and "tight", and because it is a very simple switch. I very much appreciate the help!

agentsjrc

I think I didn't read this suggestion in the post, I had a similar problem, a faulty ground connection at the armature cover terminal board.
Ground the connector and test.

Many thanks San Arthur...I checked out the armature cover ground today as you suggested. Unless I'm checking it wrong, it seems good.

I have continuity between the armature ground (a green wire, go figure) and 31 on the headlight board, as well as the battery ground. 4 ohms resistance.

All connections between the hi/lo/horn switch and headlight board are good and show 3 or 4 ohms resistance.

Battery ground to HO on the headlight board shows 340 ohms resistance.
Armature ground to HO shows 975 ohms.
Black (horn) cable on the hi/lo switch to the armature ground, and to HO on the headlight board (with the key down, at either lights off or on) shows 975 ohms for both. That surprised me.

I'm baffled...and increasingly tempted to just wire a f***&%$ headlight directly to the battery and install a toggle switch inline under the tank! I always had electrical hassles with the /5 and /7's I've owned previously, but was able to solve them with a wiring diagram and multi tester (after the local mechanics had charged hundreds and not solved the problems). But this has already cost me a lot at the mechanics, and I'm still no closer to having a bike I can ride a few miles at night...

Not sure what to try next, but I'll keep trying. I do appreciate the help!

One final thing that doesn't make much sense. When I check power at the board with the light switch on, I'm showing 6.1 volts, but the multimeter is showing a - sign suggesting that the polarity is reversed. No idea if this makes a difference or helps understand the problem in any way, but thought I'd throw it out there. Can't see any wiring problem on the board, switch, or elsewhere that would explain why.

What does it read if you reverse the leads from the multimeter?