Still in need of an exterior lamp circuit diagram for the 2009,, the one we have seems to have a lot of differences... in the BCM-C1 anyone know if the red/white or black/white is for the brakes? Those are the colors that we have that are damaged (looks like burnt together?) We also have a white/black that has been cut? Thanks!

 

Maybe this will help, unfortunately my desktop with all my PDF files is dead, when the power supply went it killed the hard drive too.



Found this lighting diagram, the white wires should be body grounds.

 

thanks for that,,,, any idea what the electric boxes are above the rear wheels behind the interior panels? the drives side has metal fins for cooling... passenger side just has two electrical boxes..??.. thanks again..

 

figured out stuff mentioned above is partly onstar... Next question... for the break lights, I have 5v reference and a ground at break light sensor on the pedal, yellow wire is 1v with breaks off and up to 3 with breaks on. No power going to green and yellows at C3 connector going back to the lights,, does anyone know if that voltage is normal and where the yellow wire goes into the BCM???

 

Finned box should be the stereo amp....and a sub box if it was installed...there's also an XM and Onstar box tucked back there...

 

The brake light switch is really a "brake pedal position sensor", sends a signal to the BCM to activate the brAKe lights. It may be TTL, but I'm not sure about that. Anyway the wires to the lights come from the computer, not the pedal.