Right Turn Signal and Brake Light Not Working

Published 07/10/2015

Products Featured in This Question

Peterson Combination Trailer Tail Light - 6 Function - Incandescent - Square - Passenger Side

(872)

$5.15

Hook Probe Circuit Tester

(60)

$12.27

Question:

My trailer running lights are working on trailer but the turn signal and brake light are not working on right side. Every thing works on the left side.

asked by: Greg K

Expert Reply:

It sounds like you either have a blown fuse or a short on the right side turn light and brake light circuit.

First, I recommend checking the trailer wire connector on the vehicle. You can use a circuit tester, like # PTW2993, to test that power is coming from your vehicle for the right turn signal and brake light. The green wire on a 4-way connector is the wire that powers your right-side turn and brake light. On a 7-way connector, the right turn and stop light wire is connected to the blade in the 3:00 position. If there is no power at the connector on the vehicle, then the problem is in your vehicle wiring. You could attach the trailer to another vehicle to ensure that the lights on the trailer work with a functioning wiring system.

If you don't have power at the vehicle side connector, you probably either have a blown fuse, if you have a factory tow package, or a short in the aftermarket wiring harness. You will want to check your fuse box if you have a tow package. If you have an aftermarket wiring harness, you will want to check all of your connection points and wires on the harness.

If the connector on your vehicle has power, then the problem is on your trailer.

You will want to inspect the wire from the trailer connector to the taillight assembly for a damaged section that could cause a short. A short occurs when a wire has been pinched, cut, or torn and the wires come in contact with the trailer. This prevents the signal making it all the way to the light. Any wires that have been damaged need to be replaced.

You will want to check the ground connections if all of your wires seem to be working. Make sure the ground location is free of rust and paint that may be preventing the light from being securely grounded. Additionally, you may want to check the blub in your trailer light to ensure it isn't bad.

I have attached a FAQ on trailer wiring that has information on troubleshooting for you.