I have a 2007 5.9 3500 in the shop with 95,000 original miles on it with only a U0164 fault in every module in the truck except in ECM and HVAC module.    The  truck has the airbag light lit and the HVAC function knob and A/C button inop. I tried a known good spare HVAC module with no improvement. I've determined the HVAC module is not getting power but would like to verify wiring is good before condemning the TIPM.   Mitchell software doesn't have the wiring diagrams I need.