The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: slickster on September 18, 2011, 06:06:11 AM

Title: charge light on when key turned off
Post by: slickster on September 18, 2011, 06:06:11 AM
r65 1984 bike charge light on when key is turned off.  The battery is so low it needs to be jump started from another bike to be stared.  Once started runs fine.  Need new battery or just a good charge?

  
slicster
Title: Re: charge light on when key turned off
Post by: Milo_357 on September 18, 2011, 07:58:44 AM
Just your charge light?  My head & tail light stay on until I flip the high beam switch!  If I forget, dead battery.  Anyone have idea what's up with that?

Dell
Title: Re: charge light on when key turned off
Post by: montmil on September 18, 2011, 08:07:34 AM
Quote
r65 1984 bike charge light on when key is turned off.  The battery is so low it needs to be jump started from another bike to be stared.  Once started runs fine.  Need new battery or just a good charge? slicster

You have a short in the electrical/charging system... somewhere.

Could be: the ignition switch itself; worn out brushes in the alternator; or possibly a bad diode in the diode board allowing a direct short to ground.

I'd look at brush condition first. The outside brush will be easy. The interior brush may require you to pull the stator. Good luck in the search.

Monte


Title: Re: charge light on when key turned off
Post by: Bob_Roller on September 18, 2011, 11:22:41 AM
Took a look at a wiring diagram, the only way you can get the "GEN" light to come on with the key in the "OFF" position, is to have a failed diode on the diode board under the front cover .

One of the diodes has failed and is allowing electrical power to come back through it, when it should be stopping it .
Title: Re: charge light on when key turned off
Post by: Bob_Roller on September 18, 2011, 11:35:22 AM
Quote
Just your charge light?  My head & tail light stay on until I flip the high beam switch!  If I forget, dead battery.  Anyone have idea what's up with that?

Dell

Most likely you have a faulty headlight switch, the tail light isn't controlled by any switch, it's wire comes straight from a fuse .

My best guess is that a contact inside the switch is staying together and you are powering the taillight backwards through the circuit .