Stop and Turn Signals Do Not Work on Trailer With Power at the Vehicle Side Connector  

Question:

Expert Reply:

When you lose the stop and turn signal functions on your trailer but you have signal at your vehicle side trailer connector, there is typically either a short or ground issue somewhere on the trailer. I would recommend starting the troubleshooting process from the beginning, just to ensure that everything is covered.

First, check the trailer connector for any debris or corrosion. If you see corrosion, it could have made its way inside of the connector. If this is the case, take the connector apart and repair or replace items as necessary. Next, check the ground connection for the trailer connector. The ground wire should be secured to a clean, bare metal surface on the trailer frame.

After that, inspect the wires for the left and right stop and turn signals. Look for any pinched, frayed or damaged sections that could cause a short. One way that you could do this is to connect your truck to your trailer and use a circuit tester, like part # PTW2993, to probe each of the circuits. This can give you an idea on where the signal terminates. If you do not have signal directly behind the trailer connector, then that is a good sign that there is a problem with the trailer connector. Probe random spots while working your way back to the trailer lights.

Finally, inspect the trailer lights themselves. Trailer lights will have either a separate ground wire that should be grounded to a clean, bare metal surface on the trailer frame, or they will ground through the mounting hardware. All ground connections should be clean and corrosion free. You could also inspect the bulbs, just to ensure the bulbs are not bad.

I have attached a help article on trailer wiring from our website. This should be helpful when troubleshooting your issue. If you cannot find a cause or solution after following these steps, let me know what you come up with so we can do further troubleshooting.

expert reply by: John H

0