Troubleshooting Brake Controller On 2008 Silverado that Releases Trailer Brakes With Pedal

Updated 01/15/2020 | Published 01/10/2020

Products Featured in This Question

Draw-Tite Activator IV Trailer Brake Controller - Up to 4 Axles - Time Delayed

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$103.67

Hook Probe Circuit Tester

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$13.33

Question:

I just installed this controller on a 2008 Silverado 2500 HD, following instructions in a video posted here on etrailer. Everything matches up but the controller literally works in the exact opposite manner that it should. Brakes are locked at the set intensity when sitting without the brakes applied on the truck, and then counts the assigned sync time to let off the trailer brakes once the brake pedal on the truck is applied. Ive checked all wires and the connections are correct. No error codes, nothing else. Just operates in the exact opposite manner in which it should. Its almost comical how well it does it too. Any ideas?

asked by: Kevin

Expert Reply:

It sounds like you have a faulty connection with the circuit that joins the brake controller to the truck's braking system. With the vehicle ignition on, but without the engine running use a circuit tester like # PTW2993 on the red wire exiting the rear of the controller. With your foot OFF the brake pedal you should not be reading any current on that circuit. If you are, it likely indicates a faulty brake stop lamp switch at the brake pedal which is kind of a known issue with GM trucks of that era.

Some have had luck connecting that red wire to the orange tow package wire, instead of the light blue striped wire. The orange wire bypasses the cruise control deactivation circuit. That's definitely worth a try before replacing the stop lamp switch.

expert reply by: Mike L