Running Lights On 5th Wheel Trailer Not Working on 2016 Chevy Silverado 3500

Published 01/13/2016

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Question:

Installed this harness on my 2016 Silverado 3500 ltz crew for my 5th wheel,I have working on my trailer 4ways,stop lights,but no trailer running lights.

asked by: Gary

Expert Reply:

Usually when there is a function that is not working on a trailer the most likely culprit is a dirty or corroded trailer connector. Make sure the trailer 7-Way, the new 7-Way, # 50-97-410, and where the new 7-Way Tees into the bumper 7-Way are all clean and free of corrosion inside, where the wires attach, and outside on the pins. While it is unlikely the connectors on your 2016 Chevy Silverado 3500 are corroded it is still worth taking the time to check the connections. I also recommend using some dielectric grease, # LT37534, between the connections to repel moisture and prevent corrosion.

You can also test the 7-Way in the truck bed using a circuit tester such as # PTW2993. If there is no power on the running light circuit, then it could be a blown tow package fuse or a damaged wire further up under the truck.

If there is power, then the issue is on the trailer side and could be a bad ground or a damaged wire that needs to be repaired somewhere on the trailer.

expert reply by: Michael H