Im doing a upfit for a customer and adding a towing package. The new van has got the plug at the rear of the van for my to plug the curt system into it but nothing is working. All fuses under the hood and seat that are labeled as trailer lights/wiring have constant power or activate when the appropriate action is pressed. I.E trailer brake fuse goes live when brake pedal is depressed.

Im now at a complete loss of where to go next as i have power everywhere but no power where its needed. I even unplugged the aftermarket plug and tested each pin in the OEM harness and none are hot

 

Do you have some wires hanging around under the dash ready for a brake controller to be installed? I think some people have found stuff up there.

https://chevroletforum.com/forum/exp...wiring-104018/

 

When I did mine I looked around for an OEM harness and controller and found none available for the Express.. Failing that, Installed this Tekonsha wiring kit and their Prodigy ID controller, which added three fuses directly from the battery and a panel-mount **** on the dash. I investigated whether it was possible to tie in to the fuse box instead but there didn't seem to be any clear instructions out there so I nope'd out and just tied it in to the battery as per the instructions that came with the kit.