Headlight & horn

[wxp]

Hi All,

I hve a problem w/ 1980 r65..after doing a spline lube this winter & getting the bike back on the road I seemed to hve 2 small but ANNOYING problems..
1-the head light only works w/the hi/lo switch all the way down past high beam..I cant seem to figure out why..there is continuity in the switch w/circuit closed as well as I can tell..there is power to the head light as well as I can tell..

2- The horn also stopped working..w/multi meter there is power when button depressed

although it has been several weeks since I messed w/it & sometimes
3 hands is better for holding & switching & pushing, but if memory serves me well, there is power to & from where it should be..

What am I missing??

[montmil]

Did these problems occur just after the spline lube work? Any issues prior to the grease job? Yanked, damaged, broken, disconnect any wires?

The BMW horn is most likely a two-wire circuit. The ground wire is more than just running to the closest grounding point. Start tracking the ground wire with a DVOM. If you have power to the horn, I'd think you have a break in the ground wire. Switch would be my last concern, right now.

Does the headlight work intermittently? Or is it out save for the passing flasher? Pull the fuel tank and check the red (usually) terminal block above the coil area. Look for corrosion. Also, the ignition switch is a potential villain in your bike. Eroded and corroded contact. Try some gently cleaner on the key and switch. Suggest disconnect of the battery ground strap first.

 Monte

[wxp]

Well, The horn suddenly & Miraculously started working this morning.

The head light only works when I push the hi/low switch all the way down past its normal position as if the problem is in the switch but I just can't believe it is since the horn started working all the sudden.

however I suppose there could be some trash in there some where. I've looked at it real well, no corrosion.

I'll keep tinkering.  I was hoping someone has had similar problems & what they might hve done to fix it or what caused it.

Thanks for the input

[Bob_Roller]

There is a relay, that turns off the headlight during engine cranking, to reduce the load on the battery .

That may be your next try for troubleshooting .

Remove the fuel tank, and see if you can hear a relay clicking when you touch the starter button .

I don't have a picture of the relay's position under the tank, but I'm sure it will get posted sometime today

[montmil]

Well, The horn suddenly & Miraculously started working this morning.

The head light only works when I push the hi/low switch all the way down past its normal position as if the problem is in the switch but I just can't believe it is since the horn started working all the sudden.

however I suppose there could be some trash in there some where. I've looked at it real well, no corrosion.

I'll keep tinkering.  I was hoping someone has had similar problems & what they might hve done to fix it or what caused it.

Thanks for the input

Guess you missed my earlier post.  I had the same headlight issue with my '83 and cured it. Suggest you do a wee bit more than simply looking at it. Zen motorcycle maintenance will take you only so far.

Your horn issue is either dirty/corroded wire terminal connections, the switch contact, or the horn itself is in a failure mode. All these items can/will produce intermittent electrical function... horn or lights.

Good luck  [smiley=thumbup.gif]     Monte