2000 suburban HVAC issues

[E.S.L.]

Hello, I’m having a very frustrating issue in my 2000 suburban. The temp control knob doesnt seem to send signal to the mode door.

  I have ruled out the temp door actuator and the HVAC control module, and the temp door will even go through the recalibration process. But then when I go to turn the knob nothing.

  I had a shop (had it in for an alignment) hook it to their Tech2 to and it came up with no faults he said except a “comm” notification. Strange thing is it worked for a little bit after being hooked to the scanner whilst the mech was test driving, but then stopped 

 

   I sure hate to tear my dash apart for nothing but I’m wondering if it could be that recirculation actuator as ive heard an issue in one of these can cause the afore mentioned problem. The recirc actuator seems to function itself though

Any thoughts would be appreciated