I have a 98 k1500 ext. cab 4x4 i have the reese hitch on and the trailer i have has electric breaks so my question is what wire in my under the dash harnes can i splice into for the "cold side stop lamp or brake light" listed in the instructions. and is it possible to use a wire under the dash to connect to the blue wire "trailer electric breaks" thanks

 

ok, for the blue wire, there is a blue wire already run from the front of truck to the plug on back. this wire is buried in a harness by the master cylinder, usually below it, either on firewall or frame. it is wrapped up and taped up with another harness. there will be a blue wire and a red or orange wire. you only need the blue wire. otherwise, you will need to run your own wire from the controller to the proper terminal on the plug on back of truck. as for the other wire, you need to tap into the brake light switch mounted on the brake pedal. it's at top of pedal, kinda buried, but not too bad. you can use a meter or test light to determine which wire has the power when brakes applied, no power when no brakes. should be either the white or yellow wire at brake light switch.