Question:
Which fuse control the 12v power on the 7 way plug on a 2009 3500hd Chevy diesel
asked by: Tony
Helpful Expert Reply:
If the 12-volt pin on your trailer connector isn't working, you've got a missing or blown fuse or the wiring connection at the fuse box under the hood wasn't finalized.
You're looking for a 40 amp fuse, located in position # 68 in the fuse box under the hood. The fuse protects one of the nearby power studs on the side of the fuse box, which is where the wire that provides power to the 7-way should be connected. If it's not, you can find the wire bundled up under the master cylinder (see photo). Simply uncoil the wire and attach it to the right hand stud on the fuse box.
Pollak Metal 7-Pole, RV-Style Trailer Socket - Vehicle End
