HVAC question

[Ice&burban]

Ok, I've got a 90 Burb. I'm wondering if I need to replace the HVAC heater/ac controls. No matter what position I put the the control on (vent, heat, def, etc.) I always get heat out the dash vents. My ac has never worked (either compres or needs charged) but I'm worried about it, always cruise with widows down in summer. Also, if I put the control on cold I still get warm heat. Not as hot when it on warm, but still heat. I did purchase a new cable from LMC (it was a little long) and change it, but it's still warm heat coming out. Do you think I need to replace the entire control set up or could it be something else?

[68Timber]

Is the switch vacuum or electrical?

[Ice&burban]

Electric if I remember correctly. It's been a year since I had it apart.

[68Timber]

I've never owned a square that new so I don't know if your blend doors are cable-operated or have actuators. It sounds like you may have actuators. Either way, it's not difficult to break it down and see then put a multimeter on it. I wish I could point you directly to the problem, but that's the way I'd approach it.

[Colt1911]

Sounds like a vacume supply problem. Good luck....

[68Timber]

Did you get a chance to look at it?

[Myers horsepower]

I had the same problem on my 1990 crewcab, it was the plastic piece on the door that the vacuum arm hooks to, you can remove the black plastic piece of the heater box behind the glove/ ashtray area to get to it, I had to make a new piece, not sure where to get a new one at.