Question:
where do you hook red wire from controller to the brake switch
asked by: Gene
Expert Reply:
Typically the wire color you would be looking for on the brake switch of your 1998 GMC truck will be white. But you will need to use a circuit tester like part # PTW2993 to verify that the wire has 12 volts when the brakes are applied and none when released.
I attached an install video that shows a brake controller install in a similar truck as yours.
Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot