Trailer Brakes Lockup When Trailer is Connected to a 2013 Chevrolet Silverado

Question:

2013 Chevy Silverado I purchased this truck before memorial weekend brand new from a dealer, I had a 2011 Ford F150 and never had an issue when my trailer was hooked up, everything worked the way it should. Now with the Chevy when I plug it in, my brakes on the trailer are automatically locked. Ive seen this problem with other Chevys and trailers and havent been able to figure out what to do. Can you help me out here?

asked by: Arnie L

Expert Reply:

It sounds like there is constant power on the electric brake output pin in the trailer connector on your new Silverado. The first step I would take is to test the truck. Using a circuit tester with an incandescent bulb, like part # PTW2993, test the pin in the 5 o'clock position on the vehicle side trailer connector (see photo).

That pin should only show power when the manual override switch is engaged on the brake controller. If it shows power at any other time, there is something wrong with the wiring between the brake controller and the trailer connector. If the trailer wiring and brake controller were factory installed, I recommend having the Chevrolet dealer inspect the issue. Altering factory wiring can throw dash codes and warnings on the truck.

If you had an aftermarket brake controller installed, sever the blue wire coming from the brake controller about 6 inches back. Test the signal at this location. Again, there should only be power when the manual override is activated. You may pickup a very small amount of power, but that is normal because the brake controller is constantly sending small signals back to the trailer connector to detect a trailer.

The photo that I attached shows the functions of each pin on the vehicle side trailer connector, in addition to testing the 5 oclock pin, I recommend testing each pin for proper function.

If the trailer connector on the truck is functioning appropriately, then we will want to take a look at a few things on your trailer. First, if you have a breakaway switch and battery installed, make sure the pin in the breakaway switch is fully inserted and not pulled or loose. Next, inspect the trailer side connector for any damage, loose wires or corrosion. I also recommend inspecting the wiring starting at the trailer connector and working back toward the brake assemblies. Look for any cut, frayed or damaged sections that could allow power to jump to other circuits.

If you cannot find a solution or the problem after following these steps, let me know what you came up with and also tell me if the brake controller and trailer wiring on your truck are factory installed or aftermarket and I will be happy to offer additional suggestions.

expert reply by: John H