Installing a Brake Controller on 1997 Chevy Silverado with Existing 7-Way

Expert Reply:

Since you have the 7 way installed already, the install is pretty straightforward. The 12V lead and the brake output wire will be ran from the 7-way up to the engine compartment. The wires terminate under the brake master cylinder. To find them, follow the brake lines down from the master cylinder. The wires can be found bundled up near where the brake lines bend to pass under the cab. The orange wire would run to the the positive battery terminal via a 40 amp inline circuit breaker, part number 9510. The blue wire would run through the firewall (find existing opening, if possible) and connect to the blue brake output wire on the brake controller. The white brake controller wire would connect to the negative battery terminal, the black controller wire connects to the positive battery terminal using a 20 amp or 30 amp circuit breaker, part numbers 38630 or 9506P. The instructions which came with your brake controller should list which breaker is necessary. The red wire from the controller attaches to the cold side of the brake stoplight switch located at the top of the brake pedal. Use a circuit tester and probe the wires coming out of the switch. When you find the wire that only goes hot when the brake pedal is pressed, tap the red wire into that circuit.

expert reply by: Mike L