Helping a friend with his son's 04 CTS......has no brake lights........bulbs are new.......switch at pedal is new......fuses checked OK.........removed rear seat and found the relay........doesn't "click" when hitting brake pedal, but if you jump it with 12V jumper wire, the relay "clicks" and the brake lights come on. Where do we need to go from here? It seems as though the trouble is in front of where we're looking......anyone have a diagram of the wiring to the switch and back to the relay? All we can find is from the relay back. Thank you all!!

 

Todays find........not getting power to the brake pedal switch.......what powers this fella?

 

Hello,
I'm having the same issue with my brake lights. Were you able to solution?

 

Yes but you probably won't want to go the route we went. ....Took out the brake switch sensor above the pedal......installed a bracket, holding an old style brake light switch, from a early 70's truck.....ran 12 volts to it and boom! Brake lights now work