Troubleshooting Reverse Lights that Illuminate on Trailer when Brakes are Applied

Question:

Hi, I just installed the wiring harness from your company. When we hit the brakes the reserve lights come on and the brake lights do not. I can try replacing the brake bulbs but I am concerned about the reverse lights. Thanks!

asked by: Melissa H

Expert Reply:

Based on what you described and the fact that the trailer wiring harness part # 118336 is a plug-in harness I would suspect that the trailer wiring harness on your trailer is wire incorrectly. It sounds like the stop/turn signal on your trailer has been mistakenly been swapped with the reverse light circuit.

When looking at the 4-way on your trailer the jacketed pin is the ground circuit, the one next to it should be the running lights, next to that should be left turn/stop, and the last one should be right turn/stop. It sounds like you have a 5-way on your trailer that has the fifth circuit ran to either of the stop/turn circuits.

You would need to swap the wiring around on your trailer connector so that it matches up with the 4-way you just installed.

expert reply by: Jameson C