2008 GMC LMM 3500 HD 4x4. all new AC system, has dual climate controls with auto settings. (Compressor, Dryer, orifice tube, Condenser) system was purged and flushed with an AC machine, then did a nitrogen purge and pressure check, then pulled back down to a vacuum rechecked and correctly refilled with new oil and refrigerant. worked great for a couple days, then only worked while at idle until you started driving and would go hot and stay hot, compressor was turning off and now will not come back on. on the scanner it is not showing any DTC codes for the AC system, the high- and low-pressure sensors check out as good. the Ambient air sensor is sending a signal but is not showing the actual temp it's sending, and I am by this time installing the new Ambient temp sensor while this is being read. also, the 4 temp sensors in the dash are all reading -50 degrees, these would be the upper and lower temp sending units located on both sides of the dash in the upper outlets and lower inlets for the dual climate control. no ground faults found, wires all Ohm'd out good to control head. also, all dash vents are working correctly, the ground wire is shared between the outside ambient air system the inside air temp sensors and originates from the control head as well as the main power supply to the sensors. i' will try to attach the wiring diagram below. and Thanks for the Help. i shoud of sold this truck and kept my 96 Dodge 12 valve.

 

Im having same issue ,did you ever figure this out??