BMW Problem... no lights

[Deleted]

Hey guys! I've got a problem with the BMW 1965 R50/2 that has me a little confused. I keep popping fuses... this is sort of a new development, though I've only had the bike running a short while. If I put a new fuse in and turn the ignition on, I'll get my indicator light. But when I turn the lights on or start the bike, it blows the fuse. Luckily, I don't need no 'lectronics to ride, but it does make starting a bit harder.

So where should I start? Its not the battery, because even without a battery, once i get the generator spinning, I should have lights... and now I do not. I think it is a short in my horn/high/low beam selector. The insulation was falling off and I'm afraid it is shorting somewhere around there. My horn has always been sporadic when it comes to working. So I figure it has always been shorting a little. maybe since it's been running and vibrating it has became worse.

I'm replacing that wiring already because I know it's a problem, i just don't know if it's the main problem.


Is there anything I'm not thinking of that you guys are suspecting?


I know troubleshooting electronics via the internet is impossible, but hopefully i'm heading in the right direction.

[felkman]

It always helps if we know what year and model bike it is. I am guessing it is your /2. There is not a lot to this system. If there are some bare wires, That would be the first place I would check but..... is your system overcharging and causing it? scratch that last part. I just read that it is both when the bike is on or off. so what that would tell me is that you have a short after the fuse.

[Deleted]

yeah its on the r50/2

thanks for the reply... If it were before the fuse, it would be easy!! I only have ~3" of wiring before the fuse!

I'll keep messing with it, I was suspecting overcharging at first since it would pop the fuse when it started running.

[felkman]

I have no fuses in my system, not knowing where your fuse is, I can only guess but are you sure it is the headlight and not the tail light or wiring back that way. Can you disconnect the wire from that crazy ignition switch inside the headlight to narrow it down a little? When are you getting the new wire loom?

[novafrk]

I agree with Felkman fix the bare / exposed wires first. Another area of concern is corrosion at any and all connectors in the entire electrical system. The corrosion will cause the resistance to go up through that connection causing an increase in amperage draw. I don't think this is the main problem here but it could be a contributing factor. If I reuse the wiring on an old bike or car for that matter, I clean each and ever connection and ground point and apply di-electric grease. It's tedious and time consuming but makes a huge difference on reliability and the performance of your charging system.

You can also remove or isolate circuts from the system one at a time. And applying power to the system again. When it stops blowing the fuse, you've found a culprit.

Hope this helps.

Nova

[Deleted]

Thanks guys! That's the route was planning to take. I have a lot of wiring from some older (1990s) vehicles that I'm using, then I'll cover them with a silicon loom.

In the past I had some problems with the tail light also...

I'm pretty sure I have a few problems and I'm trying to take care of them all now! haha

Thanks for the help!

[felkman]

You know you can buy a new wiring harness for your bike for about $85? I am sure you can make one cheaper but just thought I would put that out there.

[Deleted]

Thanks, I saw that last week. It's a really good price IMO, but I'm having "fun" chasing this problem down! If I get to April and still have the problem, you can bet your R60 I'll be ordering one.


P.S. it wasn't (solely at least) the de-insulated wires from the horn/beam selector wires.

[Deleted]

I also feel better because all of the joints are now soldered and heat-shrink wrapped.

[Deleted]

Well I have it Somewhat identified now... I hope. After fixing the headlight wiring, it was still blowing fuses when I start it up. However, if it isn't running it doesn't.


So, now my brake light doesn't work (parking light does, same bulb) nor does my neutral safety light. I'll look into that hopefully some tomorrow.

Also, I just noticed that my fuse comes off the negative side of the battery. Should I move it to the positive side? I did make sure I didn't just have the battery turned 180*.