How to Find the Stop Light Circuit for Brake Control Wiring on a 2002 Chevy S-10 Blazer

Question:

Need help finding the right wire tap to the stop light switch for a brake controller on my Blazer? I can find wires coming out of the switch just dont know which color is correct wire for tap since not finding existing factory connector on this vehicle.

asked by: Bill

Expert Reply:

The stop light switch wire should be found by function using a circuit tester, item # PTW2993. The correct wire is the one that has power only when the brake pedal is pressed. Chevrolet typically uses a light blue wire for this circuit, but wire colors change often at all vehicle manufacturers so the best way to tell for sure is to use a circuit tester.

I have linked our brake controller information page and our brake controller installation from scratch page below for you to review.

If your vehicle has a factory 7-Way connector at the rear, you will likely find a bundle of wires under the dash taped to another wire harness with a white tag on them. These wires have blunt cut ends for installation of a brake controller and should be wired as follows.

Red/Black to Black = Battery Power
White to White = Ground
Light Blue/White to Red = Brake Light Signal
Dark Blue to Blue = Brake Output to Trailer
Orange N/A Center High Mount Stop Lamp (CHMSL) = Not Used

expert reply by: Robert G