Troubleshooting T1 Trailer Wiring Harness Install that Prevents Vehicle Taillights from Functioning

Question:

Hello, I recently purchased a T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector and just got around to installing it today. After installing I tested the lights and found the passenger side tail light would not work. I removed the adapter and replaced it with the vehicle wiring directly and the lights once again worked. For some reason it wont work with the wiring harness in place. I can drive without it for now but come this fall I will need to have working trailer lights. Help!

asked by: Matt C

Expert Reply:

The first thing you should check is to make sure you had the connectors firmly seated together. If the connectors weren't totally connected together that would explain the problem. If that doesn't fix the problem I would recommend you inspect the connectors of the harness to make sure there aren't any bent pins or missing pieces that would prevent the circuit from completing.

Aside from that it would seem that the harness is at fault and would need to be replaced.

I attached an install video for this product as well as an FAQ on 4-way troubleshooting.

expert reply by: Jameson C