A/c off and engine temperature gauge is a problem I have on my h3 hummer 2008 as well. I changed my coolant temperature sensor too but that didn't work. I accidentally found out that when I play with the hvac knob the a.C light
Engine temp. Gauge acts crazy causing my a.C to turn off. I realized that I recently left the control knob that controls the air duct flow (front outlet, window air duct, floor air flow) off and my a.C hasn't stopped working since. I am convinced thru process of elimination that the problem lies within the hvac assembly somewhere perhaps the resistor. The problem started after I took my hummer in to gm dealership for blower motor harness recall replacement. Play with your air flow direction knob by leaving the knob in off position and see if you a/c light and engine temperature gauge does not interrupt your a/c. Hope this helps !
Thursday, May 4th, 2017 AT 3:14 AM