Newbie - Hi-Beam Problem

[lukasgrech]

Hi all.

I have an electric problem on my '79 R65 that I can't diagnose. Half of my Hi-Beam switch has suddenly stopped working.

The push-up position for keeping the hi-beam permanently on does not work.

I have little to no experience with electrics/electronics, so forgive me if what I suggest makes no sense.

The temporary (push down) part of the switch works, which leads me to rule out problems with the bulb itself.

Are there two separate fuses for the temporary and the permanent position of the switch? - if so, might it have been one of them that has blown?

I have removed the switch housing from the handle bar and contact cleaned the insides - still no result.

Could it be a problem with the wiring from the switch-relay-bulb? (Something I have only very basic knowledge of)

I find it quite strange that only half of the switch should suddenly stop working.

If anyone could point me in the right direction as to where I should be looking for a fault, or what the fault might be, I would be very grateful!

Side note: when I have a turn signal on, the neutral idiot light flashes in synch with the indicators.

[D Mann]

Will the momentary switch turn on the high beam with the key off?

[lukasgrech]

Will the momentary switch turn on the high beam with the key off?

Nope

[georgesgiralt]

Hello !
You can open the switch for a forensic investigation provided you keep the steel balls from jumping to infinity and keep the small springs inside the "device"...
IRC from the last time I opened one, there are a wire soldered on two places for the permanent on and pass... So maybe one solder went south...

[D Mann]

Have you checked the fuses? I think some bikes the momentary switch is not fused.

[D Mann]

Check out this article.http://bmwmotorcycletech.info/headlightrelay.htm .

[lukasgrech]

I have not checked the fuses. I will do that first, as I am a little weary of taking apart anything too fiddly like switches or electronics - I'm not confident I'd be able to build them back up!

[lukasgrech]

Check out this article.http://bmwmotorcycletech.info/headlightrelay.htm .

Thanks. Will do.

[lukasgrech]

I've checked the two fuses behind the right hand side panel, and they are not melted, and seem in good condition.

How can I go about sourcing the fault?

I am at a loss, staring at the confusion that is my wiring harness is not doing me much good haha

[montmil]

Your lighting problem, Luka, is likely something simple. The nut to crack is finding the problem and that will require a wiring diagram for your bike, possibly a VOM meter. and some time.

1979 puts your bike at 35 years old. Wire connectors corrode and fail to transfer power, switches lose their connectivity, fuses may look good but are actually failing to transfer electricity -especially those old school, euro ceramic junkers.

Troubleshooting is an art form but it's not magic. From your first post, I'd bet a couple beers that the hi-lo switch is the issue. There's a small spring and a tiny ball bearing inside. Pull the entire handlebar switch assembly, put it in a big, clear plastic bag that you can get your hands and tools into and open it up. Dirt, corrosion, bad spring, soldered terminal failed, well, you get the picture.

Trace the wires via the diagram and check each connection for power and/or continuity. You WILL find it.

[lukasgrech]

Your lighting problem, Luka, is likely something simple. The nut to crack is finding the problem and that will require a wiring diagram for your bike, possibly a VOM meter. and some time.

1979 puts your bike at 35 years old. Wire connectors corrode and fail to transfer power, switches lose their connectivity, fuses may look good but are actually failing to transfer electricity -especially those old school, euro ceramic junkers.

Troubleshooting is an art form but it's not magic. From your first post, I'd bet a couple beers that the hi-lo switch is the issue. There's a small spring and a tiny ball bearing inside. Pull the entire handlebar switch assembly, put it in a big, clear plastic bag that you can get your hands and tools into and open it up. Dirt, corrosion, bad spring, soldered terminal failed, well, you get the picture.

Trace the wires via the diagram and check each connection for power and/or continuity. You WILL find it.

Thanks, sounds like a couple of beers and a weekend job! Glad I didn't tear into the switch assembly for a 'quick look'.

Looking at the wiring, and being the organised freak that I am, makes me want to clean up and re-wire the entire system - something I'll probably save for next winter (fully aware that this would probably be the biggest learning curve I'll ever experience). Has anyone done this before, is it worth the time/money?

[Barry]

If you want a wiring diagram for the early model this is the best there is.
The quality when you zoom in is just astounding. I have it printed out on a big sheet for easy reference.  Separate legend needed unless you speak German.

[lukasgrech]

Cheers Barry!

[AlfromNH]

The high beam problem almost has to be the switch itself. Can you wiggle the switch around the up position and get the high beam to at least flicker? Does the switch have any "click" to it?

[Luca]

I wouldn't re-wire the bike unless you had cracked insulation all over the place or were already going to strip the bike down.  The wiring itself can cause problems if 1) The insulation is cracked and the wire is shorting out 2) The wire has broken or is badly corroded 3) The wiring connections are loose or dirty.

What I would do, if you want to spend a little quality time with the electrical system, is pull apart the connections, clean them, and reassemble with some dielectric grease.