Location of Factory Run Brake Controller Wiring on 1998 Suburban

Question:

I have a 98 gmc suburban and installing a brake controller. vehical came with wiring harness for the plug installed from factory. The blue line for the controller is there but cant find it in the cab. any ideas where it might be? also there is a orange wire that is supposed to be a 30amp power line, also cant locate that one at the other end

asked by: Ray C

Expert Reply:

The wires for the brake output and the 12Volt accessory lead terminate in the engine compartment. They are located under the brake booster, down where the brake lines turn to pass under the cab. They are bundled together and are wrapped in electrical tape, and can be challenging to find. The orange wire would need to be run to the positive battery terminal via a 40 amp. In-Line Circuit Breaker, part # 9510. The blue wire would need to be run through the firewall, connecting to the blue brake output wire on the brake controller. Make sure that the opening you run the wire through has a grommet to prevent the insulation on the wire from rubbing away and causing a short. The black wire on your controller would run to the positive battery terminal, using a 20 amp (part # 9506P) or 30 amp (part # 38630) circuit breaker. The instructions included with your brake controller will state which breaker is needed. The white ground wire on the controller would ground to the negative battery terminal.

expert reply by: Mike L