Troubleshooting Right Rear Trailer Turn Signal Always On When Connected To Tow Vehicle

Question:

All my running lights work and the brake light works on the left rear of the trailer. All the tow vehicle signals and brake lights work. My right rear turn signal does not work and stays on all the time once the trailer is connected to the tow vehicle—even without the ignition on. I’m sure it’s a short or a bad ground. But it doesn’t seem like it could be a fuse on the tow vehicle because everything else on the trailer functions. I need help because I have a long trip coming up in about three weeks p.s. I have been a good customer.

asked by: William H

Expert Reply:

A bad ground or short in the wiring seems likely. It could also be damage or corrosion on your trailer connector. Start by inspecting the connections to make sure they are free from damage, debris, and corrosion. Assuming that checks out I would move on to check the wiring.

Using a circuit tester like the # PTW2993, check the connection at the rear of your vehicle. Since the rear turn signal always has power, I would expect you to find this to be true on your vehicle side trailer connector. From there, work your way back until you find the issue and repair as needed.

expert reply by: Robin H