Troubleshooting A Trailer That Has No Brake, Turn, Or Running Lights

Question:

I have a 2006 travel trailer. When fully hooked up and plug harness plugged into the truck I have no running lights, brake lights nor turn singles. I have tested my truck and everything is good on that end. Any suggestions?

asked by: Andy

Expert Reply:

That indicates to me that the issue is with your trailer side wiring, since you've already verified that the vehicle side is functioning properly with a circuit tester # PTW2993.

The first thing you can do is check your grounds on your trailer, ensuring that they are clean and rust free/attached securely to a clean bare metal surface.

If you notice any of the following to be an issue, then I recommend cleaning your grounds and re-securing them to a different spot on your trailer's frame that is clean and free from rust.

If your grounds are good, you'll then want to test the functions of your trailer side wiring by using a jumper wire. To do this, you'll take one end of the jumper wire and touch it to the positive post on a 12V battery, and take the other end and touch it to each of the pins on the trailer connector.

You'll want to note for any wires that do not provide a function and trace the wire to see where the issue lies (frayed, broken or exposed wires).

If after you've done this and are still unsuccessful, feel free to come back and we can continue troubleshooting.