Electric trailer brake wiring

When we bought our 36' gooseneck, the farmer had cut all the wiring from the trailer so we had to start from scratch. Once we hooked up the controller though, the rest was pretty easy--just time consuming. At your truck's connector you should have a diagram showing you which lead is for tail lights, turn signals, brake lights and actual brake lines too. You need to run a two-conductor line (at least 12 gauge for small trailers and 10 gauge for longer trailers) to each brake magnet. One line is hot from the controller and the other is a ground. The brake magnets will work with the two wires reversed, so thats not critical--just send a separate run to each magnet. Going back to the controller--whatever brand you have--the wiring info is readily available from the vendor. Repost if you have any other questions and we'll try to answer.

Black-12volt power supply
White-Ground
Red-Goes to the cold side of your brake switch
Blue-Goes to the trailer brakes

http://www.marksrv.com/wiring.htm