Flickering Headlight

[Brent099]

My 1980 GS850 has recently developed a problem with the headlight.

At idle it seems to be fine, but after about 10 seconds of riding above 3000 rpm or so, the headlight will begin to flicker and the high beam indicator light will sort of flicker on and off. If I switch over to the high beam, it will be fine for another 30 or 40 seconds until the high beam starts to flicker, then switching back to low beam it is alright for about 10 seconds, and so on.

In my attempt to get back home last night without drawing too much attention to myself, I found that I could put the high/low switch in the middle and have both high and low beams on at the same time. The headlight didn't flicker at all in this configuration for the remaining five minutes of my ride home , but I'm sure it's not good for any of the electrical components involved.

So this afternoon I checked and cleaned the headlamp connections as well as the high/low beam switch, but with no progress.

I should also mention that the previous owner put a non-stock headlight on the bike. It actually looks like it might be an old rectangular car headlight. I've only put about 800 miles on the bike since I got it, but this is the first time the headlight has given me any problems.

I tried searching the forums for a similar problem but couldn't find one... so here I am...

What should I check next?


Thanks for your help,
Brent

[uudfourty]

Try smacking things while it's idling.

If you can whap something and it flickers, you know you've got connection problems.

If that doesn't work, then check the stator papers and currents for everything.... I guess... I really don't know. I would've suggested you check and clean all connections, but if you've done that already...

Hopefully someone that knows what they're talking about will come along and help you out shortly. :-D

[tkent02]

Haven't seen this exact issue so just a guess, but I'd double check that all the grounds anywhere near the lights are clean and tight. Strange things happen from grounding problems.

[focus frenzy]

possible it is a fluctuating R&R (regulator) check the ground and all other connections for the R&R and if you have not already, do the ground mod.

the one on my 1100E is doing the same thing, (junk electro sport) and I have a vintage SH232-12 I am going to put on.

[catbed]

now you have a cheap headlight modulator!:shock::-D

[bwringer]

I think it's a bad headlight bulb.

I've seen this happen when one of the filaments comes loose and contacts the other, or makes intermittent contact.

[Brent099]

I think it's a bad headlight bulb.

I've seen this happen when one of the filaments comes loose and contacts the other, or makes intermittent contact.

bwringer nailed it on the head, further inspection showed the headlight to be bad.

And here I was getting all ready to dig into the wiring... guess I'll just have to do a relay mod, now.

Thanks for the replies.

[uudfourty]

It's odd that it worked fine with the switch in the middle...

[bwringer]

It's odd that it worked fine with the switch in the middle...

Not really -- the fluctuation was caused by one broken filament flopping around randomly, causing intermittent contact with the other filament. With the switch in the middle, both filaments were powered.

[uudfourty]

Eh, well there ya go.