I pulled the dash on my 2007 2500 SLT 5.9 and changed the AC evaporator. After reinstalling and going to recharge my ac I noticed the AC button would not light up. Also noticed that my air bag light on the dash comes on after truck runs for 30 to 40 seconds. The fan speed switch works, but the temperature control and the air duct selector switch does not work. The AC button does not come on or the mirror defrost button. When I pull the wires off of the control panel while the truck is running the air bag trouble light will go out. If I plug the wires back in while truck is running the air bag light comes back on. This morning went to local junk yard and pulled a control switch off a truck that did not have heated mirrors and got the same results. Has anyone had this issue? Any suggestions on what to try next?

 

Does anyone know how to test the AC heater controller?

 

Did you ever resolve this problem? I've been stumped for months with the same exact issue and I can't figure out what the resolution is.