Wish I knew for sure, but in other Chevy's it was pretty easy to get the controller out.

I can see that the lower trim panels and the large trim piece around the instrument panel gauges and over to the radio and HVAC controls comes off.

I would think that is all, but do not have one to look at. Hopefully someone on here has removed the controller and will chime-in. I see that unpredicitable1 is looking at removing the controller out of his Blazer, may be he will jump in here.

 

Anything new?

 

Did you find the thread with the picture of the HVAC controller? He answered my question as to where the controller is located in post #76 (I think it was). Anyways need to remove center console (three or four bolts), remove the left and center dash lower trim panels (bunch of screws....keep track as to which goes where), remove the ash tray. According to the other thread the controller is located behind the ash tray. Should only be held in place with a couple of screws. The multi colored vacuum lines should come off as an assembly. Take the controller apart and check for corrosion, clean and reflow solder joints. Make the electrical and vacuum connections and go for a drive and see if problem is gone or still present. May need to replace it, try Rock Auto.

Are you up to trying this?