Troubleshooting 4-Way Trailer Wiring Connector that Does Not Work

Question:

Installed this kit on a 2012 CR-V but its not working. Lights work fine on vehicle but nothing works when plugged into the RV. I tried multiple ground points and even ground it directly to the battery. There is 13V back at the socket so its not the wiring under the car. The RV flat 4 plug is good and is wired correctly. Any thoughts? Thanks for your help with this.

asked by: Scott C

Expert Reply:

First thing you should do at this point is test the 4-way of the wiring harness with a circuit tester part # PTW2993 for voltage on all of the right pins when the taillight signals are being applied. Just like in the video I attached.

If the voltage checks out there but the trailer lights still don't function right then the problem is on the trailer wiring. That would mean that problem is either due to a ground issue or a short issue.

Make sure that the trailer side connector are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

If the problem is on the vehicle side then I would first recommend you double check how the harness is installed on your vehicle, make sure all of the connections are good and tight. You should check all towing related fuses and relays as well.

expert reply by: Jameson C