Troubleshooting Trailer Running Lights with 2007 Silverado 1500

Question:

On an 07 Silverado 1500, which fuses control the lighting for a trailer. My problem is that the brake lights work, the turn signals work, but the running/tail lights do not work, Have installed all new wiring and tail lights, but the running/tail lights do not light up

asked by: Lance W

Expert Reply:

The lid of your Silverado's power distribution box should have a legend indicating the function for each of the fuse positions. Check that for a 15-amp fuse labeled TLR PARK that should be in a fuse location near the outside edge of the power box. Check that it is not blown and that there is not just a dummy fuse in that position.

If the fuse is good then check that the main ground wire for both the truck's and the trailer's wiring harnesses is secured to a clean bare metal surface that is free of paint, primer, rust, grease, etc.

Sometimes a weak ground will allow some lighting signals - those that do not stay on continuously such as turn lights that blink - to work properly while others that pull more current, your running lights, will not. You can clean off the existing grounding point with sandpaper or relocate the ground terminal to a new spot for better metal-to-metal contact.

expert reply by: Adam R