After Installing Brake Controller on a 2008 GMC Sierra the Park Assist Feature Stopped Working

Question:

i followed your installation of brake controller for my truck and all went very smooth, however i see a orange wire which you did not use nor did i, my truck already had the 7 pole plug in the rear . now i do not have the function of park assist when the trailer is unhooked from vehicle, where as before it would disable automatically when a trailer was hooked up and enable when unhooked.

asked by: Mike C

Expert Reply:

The tow package wire under the dash of your 2008 GMC Sierra should not have anything to do with the park assist feature on the truck so I am not sure how it is affecting it.

The orange wire in question is an illumination circuit not used by the brake controller. You should have the Red/black GM wire attached to the brake controller black wire, white to white. light blue/white to red, and dark blue to blue.

Check the fuse for the park assist by locating it using the owners manual. It may have blown. If there was as short on the trailer it could have caused back feeding on the reverse light circuit. Also make sure the vehicle and trailer side connectors are clean and free of corrosion.

If you unplug the controller and the issue still happens then it is likely a blown fuse probably caused by a short.

expert reply by: Michael H