Hardwired Brake Controller Installation in 2001 GMC SIerra 1500

Question:

I have a 2001 GMC Sierra 1500. Im installing a brake controller by using the hardwire option.it has 4 wires. one wire goes to the positive battery post. One wire goes to the negative battery post. one wire goes to the back of the truck and connects to the blue wire on the 7 Way plug that was capped off. The last wire needs to go to the cold side of the brake switch. my brake switch has 6 wires going to it. The wires are white, orange, purple, brown, green, and blue. Do you have any idea what the cold side wire is.

asked by: Craig

Expert Reply:

You will need to test each of those six wires at the brake light switch, with a tester like # PTW2993, to find the one wire that goes hot ONLY when the brake pedal is pressed and not at any other time or with any other vehicle function activated. This wire delivers the brake signal that tells the controller to generate output and it connects to the controller's red input wire. On your truck this is likely to be a white wire.

We show that there should be a brake controller connection port on your truck, located under the dash, as shown in the linked video for a 2002 Silverado. If you have a port on your truck, you can use harness # 3025-P rather than hardwire.

expert reply by: Adam R