Troubleshooting Trailer Light Wiring

Question:

i have a 2006 gmc sierra 2500 and just bought a new utilty trailer amnd the only lights that work are the tail lights but the lights check out wit ha meter on the trailer which fuses run the towing package on the truck

asked by: Lynn W

Expert Reply:

There are a couple regular issues that can cause this. One is that the trailer has LED lights and needs a larger draw on your trailer wiring in which # 20142 will create that draw needed. The other possibility is that there is a bad ground connection somewhere on your trailer that is causing those other features not to work. I recommend checking each light's mounting hardware as the ground is often in the base and hardware. Make sure the main trailer ground and each light's ground connection is bare metal to metal and free of debris and corrosion.

Also check the actual trailer connector pins for corrosion as sometimes a little sand paper will allow the trailer lights to have a good connection and work again.

The fuses you want to check have locations outlined on page 5-125 of the online owners manual.

expert reply by: Jason S