Troubleshooting Trailer 7-Way Troubleshooting Where Trailer Brakes Lock Up All the Time

Question:

Hello, I just ordered a trailer hitch, brake controller, and 7 pin wiring harness for my 2014 Nissan Frontier from Etrailer. I installed everything. When I plugged into a popup camper I just got with electric brakes, the brakes complexly lock up. If I unplug it they release. Even unplugging the brake controller doesnt change anything. All other lighting seems to work. Had a friend plug his truck into the trailer and the brakes didnt lock up, and functioned normally. My suspicion is the pins may be mixed up, truck versus trailer, and the electric brakes are getting a constant 12v charging pin? is there anyway to fix this?. I would be very grateful for a resolution. Thank You,

asked by: Scott C

Expert Reply:

I checked your order notes and it looks like you ordered the # 118266 for your 2014 Nissan Frontier. This is the correct 7-way, but I think what you said is true and somehow the brake output and the 12 volt accessory circuits got switched.

To verify where the problem is you will want to use a circuit tester like # PTW2993 to test the pins of the 7-way for voltage on the correct pins using the diagram I attached as a guide.

I am not sure how the wires could get switched, but you could just swap the wires of the two circuits so that you get voltage on the right circuits.

expert reply by: Jameson C