Troubleshooting Vehicle Trailer Connector Running Light Circuit Not Active on 2016 GMC Yukon

Expert Reply:

If you're not getting power on the tail light circuit of your 2016 GMC Yukon, I recommend starting by checking the fuse for that circuit, which should be located in the engine compartment fuse box in slot 41. If you can give me a little bit more information as to whether you've got a factory 4 or 7 way, I can give you some more specifics to check out if the fuse isn't the issue.

If it comes down to it and you need to replace any of the wiring on the harness you could use the # 16-4B-1. I've also linked some helpful articles on troubleshooting 4 way and 7 way wiring harnesses as well, that you can have a look at as well.