Here we have a good used chassis wiring harness removed from a 2005 GMC 3500hd with the 6.6 Duramax and 4wd transmission. This is the harness that runs from the fusebox to the rear bumper. This is used, but removed from a running and driving truck. This will fit most crew short 04-05 trucks but please compare it to your existing harness plugs to ensure its the one you need, if you need any parts just inquire.