Troubleshooting Trailer Brake Controller that Only Functions When Engine Isnt Running

Updated 08/24/2015 | Published 08/23/2015

Question:

Product : Kurt discovery brake controller Truck: 2009 Nissan Frontier crew cab se Camper 1998 Coleman pop up I originally installed the controller using the factory supplied wiring in the truck. The controller did not see the trailer brakes. I ran an additional wires to the rear of the truck for the brake control and common wire. Now the brake controller sees the trailer brakes and I can adjust the controller with the ignition switch in the accessory position. If I start the truck the brake controller doesnt see the trailer brakes. If I press the brakes the controller displays a period. Same display if I try to use the manual override. Thoughts? Am I using the wrong trailer brake controller?

asked by: Jeff C

Expert Reply:

That is an interesting problem you are having, but the problem lies somewhere in the wiring of the brake controller/7-way. The only way a brake controller is going to work properly with the key in the ACC position but not when the vehicle is running has to be due to wiring.

Check to make sure there are no shorts between the two wires you ran to the rear of the 7-way. It sounds like you ran a wire for the 12 volt accessory circuit and an additional wire for the brake output.

You might check that a stop/turn circuit hasn't shorted out to the brake output circuit as well. Basically something is shorting out to the brake output circuit and causing it to prevent the brake controller from functioning.

I attached a help article on troubleshooting brake controller installs for you to check out as well.

The Curt Discovery # C84VV should work just fine in your vehicle.

expert reply by: Jameson C