Running Lights on 2 Trailers Not Working When Connected to a 2016 Chevy Silverado 2500

Question:

I have only my brake and turn signals on my trailers. I had plugged in two trailers that previously worked with all lights and now I have no running on either trailer but only brake and signal. I am assuming it is now the truck. I have a 2016 Chevy Silverado 2500HD full bed. Can you you help?

asked by: Russ K

Expert Reply:

I will be happy to help. This sounds like an example of a corroded trailer connector either on the 2016 Chevy Silverado 2500, the trailers, or both. The first thing to do is make sure that the truck and trailer connectors are clean and free of corrosion inside, where the wires attach, and outside on the pins. Using a wire brush could work but I recommend a nylon brush such as # 814092 to avoid short two pins together.

If that does not solve the problem, you can use a circuit tester such as # PTW2993 or a meter if you have one to test the truck side connector. Have someone sit in the truck to operate the lights while you test the connector. If there is no power on the running light pin during this test, then the issue is on the truck, most likely a bad fuse or relay.

In the fuse block under the hood there is a fuse in location 15 for trailer parking lamps that you can check. There is a relay in location 63 for trailer parking lamps. The easiest way to check for a bad relay is to use a known good one in place of a potential bad one.

If there is power on the truck side running light pin then the issue is on both of the trailers, likely a pinched or broken wire or bad ground connection to the trailer frame.

expert reply by: Michael H