Troubleshooting a T-Connector Vehicle Wiring Harness for 2013 Ford Explorer

Question:

Hi, I purchased a Curt # C56278 harness and installed it on a 2013 Ford Explorer. At first I thought I might have missed the wiring, but after double checking it is correct. The issue is if I put the left directional on, all directional and brake lights flash. If I put the right blinker on, the left directional stays lit. I tried switching the left and right directional wires and the same thing happens except the opposite directional stays lit. The camper attached is brand new, and I made sure the ground on the harness was a good connection. What else could be causing this?

asked by: Thomas E

Expert Reply:

We are going to begin a process of elimination to solve this problem, starting by checking the 7-way functions. Start by using a circuit tester such as # PTW2992, to test the individual outputs from vehicle's 7-way just to make sure they are all working as intended. If that proves to be an issue, we know the problem is on the Explorer's side, if not, we can narrow it down to the issue being on the trailer.

You mentioned that you checked the ground on the Curt # C56278 harness, but be sure to check the ground on the trailer side, ensuring it is attached to a metal surface without rust and is clear of any debris.

You will also want to take a look at the connectors on both the vehicle and trailer side, ensuring they are free from any type of dirt or corrosion. You can go ahead and test the trailer's lights by using a 12V battery and applying power to each circuit on the trailer plug.

If none of these steps resolve the issue, let me know and we can look into further options.

expert reply by: Kyle S