The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: chewy4x4 on March 23, 2010, 10:31:00 AM

Title: I lose lights and there's more!!!!
Post by: chewy4x4 on March 23, 2010, 10:31:00 AM

Ok this just started last week. As I am riding if i get the bike up in the RPM say 4000+ I will most likely have a high pitched whirrr from the front metal on metal like. I lose lights but not the ability to ride or ever accelerate. I believe it to be the Alternator rotor but I have yet to check. I am at Uni right now so I cant answer many questions. Has any one heard of this? Any suggestions on what I should do...other than pull the cover and check.

Title: Re: I lose lights and there's more!!!!
Post by: nhmaf on March 23, 2010, 01:26:10 PM

If the alternator fails (usually open circuit) or a brush fails (open circuit) you won't immediately lose your lights, though they will begin to dim.  The "GEN" idiot light on the dash panel should light up.   You can put a multimeter on your battery to check the voltage when the engine is revving around 3500 RPM or so - it should be around 13.5V if your alternator, brushes, and diode board are working.

If it is a high pitched squeal, it could be that your timing chain tensioner is worn out and/or broken.

Title: Re: I lose lights and there's more!!!!
Post by: chewy4x4 on March 23, 2010, 04:15:11 PM

Yep high pitched squeal. And no lights come on because no lights will come on. And when I slow down below 3500 the sound goes away and the lights come back. The squeal is variable with the rpms.

Oh and the bike only has 6000 miles on. Yes that is correct.

Title: Re: I lose lights and there's more!!!!
Post by: nhmaf on March 23, 2010, 04:43:37 PM

That is very odd - do check the voltage as measured at the battery both above 3500 RPM and at idle - this may provide additional clues.

Title: Re: I lose lights and there's more!!!!
Post by: chewy4x4 on April 03, 2010, 12:15:25 AM

So I found out the problem. It seems that the internal contacts on my starter relay were to close and were making contact sending signal to the starter. The reason I had no lights was because the lights go out when the bike is started. I pulled the relay and opened the cover spread the contacts just far enough that would only make contact when the signal was sent from the switch. No more issues.

Title: Re: I lose lights and there's more!!!!
Post by: bruce_launceston on April 03, 2010, 12:18:42 AM

Nice work diagnosing that curly one and an easy fix!

Title: Re: I lose lights and there's more!!!!
Post by: chewy4x4 on April 03, 2010, 12:22:06 AM

Thanks bruce. How is winter comming along?

Title: Re: I lose lights and there's more!!!!
Post by: bruce_launceston on April 04, 2010, 06:26:16 AM

Probably the best time of the year at the moment, nice sunny day about 21 degrees C.
Last rain was a short shower middle of last week. I ride to work every day and haven't needed my waterproofs for a couple of months. (It rained the few days I had the bike off the road for the tank reline.)