Troubleshooting Stop Turn Circuit of 2014 GMC Yukon XL Trailer Wiring Not Functioning

Updated 02/18/2020 | Published 02/17/2020

Question:

Its a 7 pin. My left turn signal and Brake is not working on the trailer. All work fine on the truck. I tested with a meter and all other functions work. There is no power to that pin when the turn signal is on or the brake is applied. If I jump the yellow wire from the truck tail light I can get the turn signal to work. How do I find the problem - the wire or a connection. Where do I start. Thanks

asked by: Tom

Expert Reply:

First thing I'd check is for a blown fuse under you hood. That's the most common issue that kills a trailer wiring circuit and is very easy to fix. Next possibility is corrosion on the pins of the trailer wiring. To fix that take some sandpaper to all of the pins on your 7-way. If the 7-way is looking pretty rough it might be best to replace it with a new one like the # A10-7072VP and you'd have an all new connector. Aside from that you'd have to trace wires to see where the issue might originate.

expert reply by: Jameson C