Troubleshooting Trailer Lighting Not Functioning on a Trailer with Damaged Wiring

Question:

118379 Wiring harness for 2000 toyota tacoma. Have 11.1 VDC between ground and brown pins, no voltage on next two as is normal Im guessing-bounces accordingly with both signals, seperate pins. Is 11.1 VDC sufficient current for the trailer. I have no lights, but wiring by tongue is somewhat damaged and ground white was severed. I wire nutted to try and test but no change. Any info could be helpful, thinking running new wire segment from tongue to lights. BUt wanted to make sure power out of the harness on towside sounds good.

asked by: Ben

Expert Reply:

It sounds like the T-One Vehicle Wiring Harness # 118379 that you referenced is installed correctly and is functioning properly. It also sounds like the trailer wiring issues you are experiencing are related to the damaged ground wires you have on the trailer.

If you clean up the wiring and make sure everything is grounded properly your trailer lights should begin to function properly.

I attached a couple FAQ articles on trailer wiring and 4-way troubleshooting for you to check out as well.

expert reply by: Jameson C