Trailer 7-prong plug
 

I have a 2007 Silverado 2500HD that came factory equipped with a brake controller and trailer 7-prong plug. When I hooked up my trailer I realized there is no constant 12 volt power coming through the plug.
The GM diagram shows which spade of plug is constant power but it tests dead. Did they just forget to hook it up or is that the way they come from the factory? Thanks for your help

RE: Trailer 7-prong plug
 

Read this from Prodigy. You may no have to bother with the brake contol wire since it came from the factory with a contol.

There are two wires under the hood that have to be connected to make the tow package

functional, one is the power wire to the brake control and the other is the battery charge

line to the 7 way connector. These wires are both Red/Black with eyelets connected to

them. They are coiled up under the hood and will need to be connected to the under hood

fuse box. One of these wires can be found located between the fuse box and the left

(drivers) side fender. The other is located under the master cylinder/brake booster

assembly.

The battery charge wire and the brake control wire have different size eyelets on them

and will connect to the threaded studs under the Gray handle of the front of the fuse box.

The two studs are also different size.

Note: GM does not supply the nuts required to secure the wires to the studs. These can be

obtained locally.

Important: Raising the Gray handle more than 3/8 of an in to gain access to the

studs

If disconnection occurs you may have to see your local GM dealership for repairs.