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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: tsunamiblack on October 11, 2012, 04:27:46 AM

Title: lights started flickering on ride home last night
Post by: tsunamiblack on October 11, 2012, 04:27:46 AM
Hello Everyone,

I wonder if anyone can help, last night my lights started flickering slightly on the ride home, more than a little bit worrying as I live in the country and there are no street lights etc. :yow It effected all my lights as far as I could tell, dipped headlight and main beam also clock lights. It only appeared to do it at around 2500-3000rpm, (I can only guess this as my rev counter spends most of its time off the top of the scale). If I pulled the clutch in and let the revs drop to idle the lights were fine. Is this a sign that the regulator or the alternator is giving up. The bike has done very little over the last 10 years and I've only had it a short time, the more I ride it the better it seems to get!

Cheers
Title: Re: lights started flickering on ride home last night
Post by: Opus on October 11, 2012, 09:31:55 AM
I would start by looking for a loose/bad ground wire along the path for the lights.
Also check the grounding point(s) for dirt or corrosion build up.
It could be that simple a fix, but I'm sure the MASTERS will chime in with thier thoughts on this soon to.

Let us know what you find.
Title: Re: lights started flickering on ride home last night
Post by: Inge K. on October 11, 2012, 10:23:59 AM
Most probably a bad ground at LSR coil, which is grounded through the starter brushes.
Then you need to pull the starter and clean the commutator and change the brushes.

To verify...ground the starter input temporary, after the bike have been started.
Do not touch the starter button with the temporary ground connected.
Rev the engine to check if the flickering is gone.

Inge K.
Title: Re: lights started flickering on ride home last night
Post by: healthy on October 11, 2012, 12:20:48 PM
no joke, i logged in today to post the exact same thing, though mine happens at idle yesterday and would go away at any rev. (noticed through the reflection in the car ahead at a light.) it did seam that the light would dim/flicker as the RPMS dropped (i do need a valve adjustment and my TB synced) could this be a different issue? alternator straining or about to go?

plenty of streetlights here in chicago, but i was just worried it was the start of something that would leave me dead in the water at a light turning green.

when i got home last night i was going to shoot a video of it after i parked my bike, and like most good electrical gremlin issues, it wouldn't show itself again. (though the engine continued to sound the same, with a slightly wavering idle.)
Title: Re: lights started flickering on ride home last night
Post by: wmax351 on October 11, 2012, 02:17:47 PM
Its the load shed relay, as inge k said. Clean the starter. Polish the commutator and clean it out.
Title: Re: lights started flickering on ride home last night
Post by: tsunamiblack on October 11, 2012, 02:36:27 PM
Thank you for all your replies! I will give it a clean this weekend hopefully. I'll keep you posted.

Cheers
Vic
Title: Re: lights started flickering on ride home last night
Post by: frankenduck on October 11, 2012, 04:30:16 PM
You might also want to check for a loose connector on the back of the headlight bulb.
Title: Re: lights started flickering on ride home last night
Post by: K75RT Keith on October 16, 2012, 11:13:14 AM
I've had the light issue too.  It improved after I cleaned the ground from the starter and under the tank.  But, I still have to clean the starter and replace the brushes.

Healthy,
Have you checked for air leaks at the throttle bodies?  The TB's have 2 screws  don't mess with the silver screws with the blue locking paint. They are factory set and unless there the po adjusted them they should be right on.  The manual I have recommends only adjusting / synchronizing the throttle bodies after checking and correcting any air leaks, the valve clearance is adjusted to spec and the air filter is new/clean.
Title: Re: lights started flickering on ride home last night
Post by: healthy on October 16, 2012, 03:59:10 PM
i know i do need to dive in and adjust the valves, i just haven't gotten around to getting the tools to do it safely without damaging anything. that is slated for this fall before i winter the bike.  (i've also taken the warning about the locked screws for the TBs to heart, so i won't accidentally start adjusting them.)
Title: Re: lights started flickering on ride home last night
Post by: ReneZ on November 04, 2012, 05:02:51 AM
There's a difference between checking the clearance and adjusting the clearance. For the first bit you only need feeler gauges and for the latter some special tools are handy. As these bikes don't change clearance too much with normal use I'd do the first bit now. Quite possibly you don't need to adjust and at least you know the status and go from there.
Title: Re: lights started flickering on ride home last night
Post by: k on November 04, 2016, 10:00:31 PM
Thanks for the tips in this thread. My headlight, taillight, and turn signals were flickering. My horn would work intermittently. My signals appeared on the dash as flashers - both left and right would illuminate and pulse. The horn worked intermittently. The starter would take a few presses to engage.

Swapped the starter, and all is well. Not sure why BMW has a ground loop running through the starter. That's bizarre.

Should I rebuild the old starter? I'm thinking that I don't want to toss it in the trash.
Title: Re: lights started flickering on ride home last night
Post by: Elipten on November 04, 2016, 10:58:27 PM
Rebuild and keep


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Title: Re: lights started flickering on ride home last night
Post by: stokester on November 05, 2016, 08:23:10 AM
Should I rebuild the old starter? I'm thinking that I don't want to toss it in the trash.

Probably just needs a good cleaning.