Electrical Problem?

[hombremoto]

Hello!

I have come across a Strange Electrical Problem

The BMW Model is a R1200GS Adventure, 2007 with around 20.000 miles.
All of a sudden, since a month or so, with no apparent cause has the following symptoms:

The low and then the high beam light bulbs burn out all too often, maybe every 200 miles.
At speeds over 3500 rpm the warning lights at the instrument panel come on and some elements stop working such as speedometer indicator.
However when the speed RPM is decreased to below 3500rpm normality is restored.

Any ideas at what could be at fault?

Many thanks for the feed back

[marc]

Alternator/voltage regulator? I'd put a voltage meter on the battery terminals and check the voltage at various RPM. Doing this in neutral is fine. If the voltage rises more than about 14.4 volts you've got a problem in that area.

[hombremoto]

Ok, Thanks
I'll check the voltage
Cheers

[hombremoto]

Hello!

This is the voltage reading at the battery connectors at several rpm with the bike in neutral


motor rpm [volts] actually
k expected measured

contact off 12 12.5 - 13.16 - 12.96 (three measurements)
contact on 12 12.26 - 12.8 (two measurements)
idling 12 14.27
1.1 12-14.4 14.15 - 14.27
1.5 14.4 14.17
2 14.4 14.4
2.5 14.4 14.7
3 14.4 14.08
3.5 14.4 14.07
4 14.4 14.06
4.5 14.4 14.05
5 14.4 14.04
6 14.4 14.03

Except the fact that the highest voltage is reached at 2.500rpm, 14,7 volts, it seems to me that the volts readings are ok.

So the trouble apparently would not be at the generator area.

Any suggestions as how to carry on from here to pinpoint this strange electical problem?

Many thanks

[hombremoto]

Here goes the same data; the table previously sent was confusing to read. Sorry about that

At several rpm, volts measured at battery (bike in neutral)

contact off 12.5 - 13.16 - 12.96 volts (three measurements)
contact on 12.26 - 12.8 v (two measurements)
idling 1.100rpm 14.15 - 14.27 v
1.500 rpm 14.17 v
2.000 rpm 14.4 v
2.500 rpm 14.7 v
3.000 rpm 14.08 v
3.500 rpm 14.07 v
4.000 rpm 14.06 v
4.500 rpm 14.05 v
5.000 rpm 14.04 v
6.000 rpm 14.03 v

Any suggestions?
Thanks again

[marc]

The voltage looks OK. At this point I'd start suspecting a wiring or connector issue. My assumption is that some vibration at above 3500 RPM is causing an intermittent connection.

I'd hope that the bike would log some faults when the problem happens. Either find a friend with a GS-911 or have a dealer check for any faults. That might lead you in the proper direction for a fix.

[RickC]

Check the connection on the instrument cluster. Pull it off and spray it with some WD40 or LPS1 and reconnect and make sure it locks in place. Do the same with the headlight connector. As Marc said, sounds like a loose or corroeded connections.