After Installing Brake Controller on 2011 Chevy Silverado, Trailer Brakes Lock Up Right Away

Question:

I have watched the video and wired my 2011 1/2 ton Chevy P/U accordingly, but trailer brakes will not release unless you unplug them.

asked by: W .

Expert Reply:

Do you happen to have a 6-Way trailer connector or are you using a 7-Way to 6-Way adapter? Usually when this happens and a 6-Way is involved, it means that the 12-volt circuit and brake output circuit are switched.

On just a 7-Way, there could be a short that is causing power draw to the brake output pin. And it could be a problem with the brake controller.

There are some tests you can do to test the brake controller. In the truck cab you will need to sever the blue wire several inches from the back of the controller. Then use a circuit tester such as # PTW2992 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override or brake pedal. If it shows power at idle, then there is something wrong with the controller and it will need to be replaced.

If it tests fine, then reconnect the blue wire. Then move on to the truck side trailer connector. Many times, dirt or corrosion can cause a short in a trailer connector. Make sure the truck and the trailer side connectors are clean and free of corrosion inside and out.

You can test the brake output pin and it should only show power with the manual override. If it shows power any other time, then there is a short somewhere between the connector and the brake controller you will need to track down.

If the truck side checks out fine then it could be the wiring to the brake magnets or the magnets themselves. Inspect the power wires to the magnets and look for pinched, frayed, or damaged wires and fix as needed. Make sure the ground wires are attached to clean and corrosion free bare metal surfaces.

You can visually inspect the magnets and if you can see the copper windings coming through the magnets will need to be replaced. To further test the magnets you can follow the help article I have linked. I have also included some help articles on testing and troubleshooting brake controllers for you.