Troubleshooting Trailer Lights Not Working Properly for 2003 Chevy Silverado Factory 4-Way  

Question:

Expert Reply:

If the issues you described are happening when any 4-Way trailer connector is hooked up, we at least know the problem is somewhere on your 2003 Chevy Silverado (we don't need to worry about the wiring on the trailer).

What I recommend doing first is simply visually inspecting the 4-Way connector on the truck. Look for any debris or corrosion built up inside the pins that needs to be cleaned out. Corrosion inside the pins can lead to a short, which would explain the crossed-up circuits that are showing themselves when turning on the headlights in the Silverado.

If this doesn't resolve the issue then there's something going on with the factory wiring. You can try tracing the wiring as far up the truck as you can from the back of the 4-Way connector, looking for any pinched, exposed, or damaged portions that need to be replaced.

It will probably be pretty difficult to give an in-depth inspection to the factory trailer wires, so your best option may be to simply install a hardwire harness like the Tekonsha # 18252 that you can use to splice into the tail light wiring. This will bypass the factory harness altogether and since you know the tail light circuits are working on the Silverado (since the lights work fine without a trailer attached), this will work great.

expert reply by: Chris R

0