Troubleshooting Trailer Wiring that Stopped Working

Updated 06/18/2024 | Published 06/04/2024

Question:

Hello, I bought this harness and a trailer hitch about a year ago for a 2017 Pathfinder. I installed easy, no issues, and used it to tow a camper that I built. Everything worked fine last year. This past weekend we were going to go camping I hooked up the trailer and plugged in the wires, but the lights on the trailer did not work none of them. I figured it must be the trailer wiring so I bought a wiring kit and re-wired the trailer 8foot trailer, simple wiring. Still, none of the lights work. Is it possible that this trailer wiring kit isnt putting out enough juice to the connector?

asked by: Andres M

Expert Reply:

Hey Andres, normally when this happens after pulling trailer out of storage from the winter the problem is corrosion that developed on the pins of the trailer wiring connector. I would try taking sandpaper to the pins of the 4-way on the vehicle so that the connection can be made again. If that doesn't work let me know but it's almost always this.

expert reply by: Jameson C

Andres M.

6/18/2024

Thank you Jameson! So this ended up being a lesson on being thorough. Just about every troubleshooting article/video stressed the importance of checking grounds. I had visually checked them (yep, it's still there, and it still has a screw/bolt attaching it). After looking/replacing all the fuses and not getting results, I started checking all the connections by unscrewing them, cleaning them, and re-attaching. The ground on the vehicle was 'still there, with a screw holding it'; but said screw was in fact not holding the ground against the chassis. After tightening this one, it was like magic - everything worked. So yeah, check your grounds.

Jameson C.

6/18/2024

@AndresM That's awesome! Yeah ground issues can be an absolute nightmare since they can look totally fine but in reality there's something off but I am glad you got it figured out.