Trailer Brake Wiring for Tandem Axle Brake System

Updated 07/09/2009 | Published 07/07/2009

Question:

How does the wiring route for a tandem axle brake system? i am looking for a diagram of how it routes from axle to axle. I have a 7 pin, wire for the brakes start with a blue wire that goes to a sensor looking thing with a brown and green wire coming out. i need to know where the wires go from there. I just traveled the alaskan highway and the wiring got destroyed by the gravel road stretches we had to travel. thanks for your help if you can.

asked by: Edward

Expert Reply:

I'm not sure what the sensor you describe is for. Typically trailer wiring is color coded so that right turn and brake light signal is carried by a green wire, and the brown wire carries the running light circuit. The brake output circuit is usually carried by a blue wire which travels to each brake magnet, where it attaches to one lead from each magnet. The other lead from each magnet will ground to the trailer frame. I'll give you a link to a typical trailer wiring diagram.

I also included a link below to a video of a trailer being wired for lights that you might find interesting also.

expert reply by: Mike L