Troubleshooting Trailer Lighting Where One Side Running Light and Other Side Blinker Doesn't Work

Question:

Good Day, I recently installed the Wesbar Wishbone 4-Pole Flat Trailer Connector Wiring Harness. The passenger side running lights all work but the turn signal/brake doesnt and the drivers side running lights dont work but the turn signal/brake does lol. Any advise. Thanks,

asked by: Matt

Expert Reply:

Usually when there is odd trailer lighting behavior like this that doesn't seem to make much sense the issue is weak grounds on the trailer. I would go over the grounds for each assembly as well as just make sure all of the wires are currently connected properly.

I attached a help article link on trailer wiring troubleshooting for you to check out as well.

expert reply by: Jameson C