red wire coming out of controller has no power from brake light switch but truck has brake lights 2005 gmc C8500
Expert Reply:
It sounds as if you might have that red wire tapped into the wrong circuit. The red wire coming out of the controller would need to be connected to the cold side wire from the brake switch. This wire will only show current when the brake pedal is pressed. Sometimes the necessary wire can be difficult to find. The best thing to do is find the wiring harness exiting from the top of the brake pedal, and use a circuit tester, like part # 40376, and probe each wire until you find one that goes hot when the pedal is pressed.
expert reply by: Mike
