Troubleshooting Gooseneck/Fifth Wheel 7-Way Install Where Left Turn Signal Stopped Working

Question:

Hello I just installed this harness today on my new ’15 GMC Sierra 2500HD. It seems I have all functionality except no left turn signal. Do you have suggestions? Thanks

asked by: Kyle

Helpful Expert Reply:

Does the left turn signal work on the 7-way that is at the rear of the truck? If so then the problem is that the connectors aren't making decent contact. Try uninstalling the # 41157 and testing to see if the left turn circuit works on the factory 7-way with a circuit tester like # PTW2993.

If it does work then the problem is either in the connections made when installing the connector or somehow the connector is bad (not likely).

If the turn signal on your truck isn't working you would want to check under the hood of the truck for trailer turn signal fuses and replace as necessary.

Most likely just ensuring the connector is fully seated will fix the problem.

expert reply by: Jameson C