Troubleshooting Trailer Lights Not Working and No Power at the 7-Way on a 2000 GMC Yukon

Question:

I am not getting any voltage on my factory 7 prong plug. My Stop and turn signals have not worked for some time now my running lights stopped working. I put a volt meter on and not getting any reading. My lights work on the Yukon. Any suggestions on how fix it?

asked by: David T

Expert Reply:

There could be a couple of causes leading to the lighting malfunction you are experiencing. The first things I would check are the ground connections on the vehicle side 7-Way, trailer side connector, and the grounds for the lights on the trailer. On most trailers, the lights ground through the mounting studs. Make sure that at each ground location, there is no dirt or corrosion. A bad ground connection is one of the leading causes of lighting malfunctions.

You can also probe the wires using a circuit tester # PTW2993 further back behind the plug on the vehicle side to see if the plug itself is the problem. If it needs to be replaced, we have the Replacement Multi-Tow 7-Way and 4-Way Trailer Connectors, # 30955, which is designed to fit your 2000 GMC Yukon (use this part if your Yukon has a round plug and cap instead of a bundle of wires above the spare tire. For a bundle of wires, use # PK11898). You may also need to make a few connections under the hood or check for some blown fuses. I have included a link to an FAQ article that should help.

If the 7-Way on the trailer is old, it may need to be replaced with a new 7-Way. Over time, the internal connections can corrode or pull away causing a bad or no connection. I have included a video below showing the replacement of a 7-Way using a Pollack Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End, # PK12706, that should help.

expert reply by: Michael H