Why Would 2003 Chevy Silverado Have 8 Wires Ran to Trailer Wiring Bundle

Question:

My 2003 Chevy Silverado trailer hook up has 8 wires instead of just 7 when I went to replace the hook up . How do I hook it up?

asked by: Chris

Expert Reply:

Most likely there's an extra wire that was intended to run up to the third brake light of a camper shell mixed in with your trailer wiring harness as this is very common with 2003 Silverados like yours. So your best option is to test all of the wiring with a circuit tester like # PTW2993 and wire it to a new 7-way accordingly. I attached a diagram for a 7-way for you to check out as well.

If you find a circuit that activates with only the brakes being applied and not with either of the turn signal circuits that would be the circuit that would run to the camper shell third brake light.