Here we have one used transfer case wiring wiring harness removed from a 2003 GMC 2500hd with the 6.6 Duramax, 6sp manual transmission and MANUAL T-CASE. This should lots of 01-05 duramax trucks 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.