Troubleshooting Curt Brake Controller Installation in 1990 Chevy Silverado  

Question:

Helpful Expert Reply:

If your brake controller is a time-delay type like the Curt Venturer # C74VV it should activate the trailer brakes either when you press the brake pedal or press the manual override lever. But if you have a proportional type controller like the TriFlex # C24VV, which is triggered by inertia (from the motion of your truck) then the brake pedal will activate it ONLY if you are moving. With both types of controller the manual override lever should activate the brakes to the selected power level.

Your vehicle lights causing the controller to activate does indicate a problem in the wiring installation. The controller's red wire is the input trigger that tells it you are applying the brakes. It wounds like this wire is connected to the wrong circuit. It should be connected to the cold side of the brake light switch that is above the pedal; this is the circuit that goes hot ONLY when the pedal is pressed and at no other time. If the wire used also goes hot when the lights are on then this suggest the controller's red wire is connected to the wrong circuit.

If you are using a quick-connect wiring adapter to install the controller, Curt part # C51342 or the other one referenced, part # 3025-P, then it is possible that this harness was mis-wired. This could cause the issue if the red wire was being connected to another circuit in the truck. You can test the wiring adapter by plugging it into the under-dash port and applying a circuit tester like # PTW2993 to the contact for the red wire on the other end. If a signal appears at any time other than when the brake pedal is pressed (such as when you turn on the lights) the this tells you that the wiring adapter has the red wire connected to the wrong pin on the vehicle-end connector.

expert reply by: Adam R

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