Trailer Brake Lights Do Not Work on a Trailer Towed by a 2001 Chevy Astro

Question:

I hooked up a 4 pin plug to the trailer harness everything works except the brake lights.

asked by: Chris

Expert Reply:

First, the correct wiring harness for a 2001 Chevy Astro is # 18252. This harness splices directly into the tail light wiring of the van. The brake lights and turn signals are on the same circuit. Check to see if the brake lights on the van are working. If they are then the most likely issue is a bad ground connection or a dirty/corroded trailer connector.

Ground issues normally show up when there is more load on a system such as the constant 12 volt draw of the brake lights. You will want to make sure that the ground on the vehicle side wiring harness is attached to a clean and corrosion free bare metal surface. Do the same for the main trailer connector ground and the grounds on each of the tail lights.

Also make sure that the vehicle and trailer side connectors are free of dirt and corrosion.

If the brake lights on the van are not working then you need to look at the van wiring and check the stop light fuse to see if anything needs to be replaced.

expert reply by: Michael H