Troubleshooting Curt TriFlex OL Error When Trailer Connected on Chevy Silverado

Question:

I installed a curt triflex in my silverado and the first tow it worked fine. Second tow it shows an OL once the trailer is connected. Shows the numeric setting with trailer disconnected. If I connect the trailer to my other vehicle, the trailer brakes work properly with that controller. When I connect another trailer, with known good brakes, I get the OL again. Using factory wiring harness and plugs, and no shorts on the blue line or in trailer. Plug looks good, too. Think the unit is defective or should I replace the 7 pin plug in the factor bumper, even though it looks good?

asked by: George

Expert Reply:

The OL error on your Curt TriFlex Trailer Brake Controller # C24VV indicates a short or overload. Since it sounds like the same controller works on a different vehicle I would definitely say the issue is with your Silverado. Before you start replacing parts there are a few different things I would try.

First, I would clean the 7-way connection on your vehicle. Might as well clean the trailer connection while you're at it. This will get rid of any potential corrosion on the connection. It sounds like visually it may appear to be ok but I would still clean it to be sure. I would also check the ground connection. Make sure it is securely connected to a clean, bare-metal surface. If you are still getting the error, I would double check the wiring using a circuit tester like the # PTW2993.

I have attached a helpful article on troubleshooting issues with brake controllers for your reference.

expert reply by: Robin H