Here we have a used chassis wiring harness removed from a 2001 GMC 3500hd extended cab short box with the 6.6 Duramax and 4wd transmission. Good used condition and fully functioning with only moderate signs of wear and use as would be expected on a 20+ year old truck! This is the harness that runs from the front fuse box down the frame all the way to the back. This is used, but removed from a running and driving truck. This will fit 01-02 trucks with the same configuration and probably even 03-04+ but please compare it to your existing harness plugs to ensure its the one you need, these are non returnable. if you need any parts just inquire.