Brake Wiring Diagram Trailer. The Trailer Brake Control and Additional Plug-In Wiring Harness. The following trailer brake wiring diagram contains detail illustration of the typical brake applied in trailers.
The Brake Controller comes with a wiring harness that is the kind you have to splice into your vehicle's wiring. In most cases problems with electric trailer brakes occur either because of corrosion in the trailer connector or a break on the wiring between the connector and the brakes. The following trailer brake wiring diagram contains detail illustration of the typical brake applied in trailers.
Then i'd suggest, taking the connector off of your trailer, exposing the wire ends.
The trailer has electric over hydraulic brakes.
In the electric system the braking system consists of brake controller, stoplight wire, battery, hydraulic. The following trailer wiring diagram(s) and explanations are a cross between an electrical schematic and wiring on a trailer. Run again thru your diagram and turn on each light of the truck.