Troubleshooting the Curt T-Connector with 4-Pole # C55510 When the Tail Lights are not Working

Published 12/29/2016

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(84)

$42.58

Hook Probe Circuit Tester

(66)

$13.04

Question:

My blinker works but my tail light does not light up?

asked by: FLOYD A

Expert Reply:

First, check the connections on the vehicle that plug into the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, # C55510. If one of the pins in the connector is bent or misaligned, then this could be the reason your taillights are not lighting up.

If the the connection at the vehicle is good, then you can check the signal output at your vehicle's 4-flat plug. Have someone sit in the cab of the vehicle to operate the lights and turn signals. Using a 12-volt probe, like # PTW2993, turn on lights and use tester on the brown, yellow and green wire leads. If all three light or sound the tester, then the powered wires are ok.

Now you will have to check the lights and the wiring on the trailer. You can use the tester to see if you are getting power to the taillights when connected to the vehicle. The turn signal and taillight travel on different wires, so there may be an issue with the taillight wire somewhere along the trailer. Check the light bulbs and the ground to make sure they are not damaged as well.

I have liked a help article on testing trailer wiring for you to view.

expert reply by: Jared P