'95 Blazer LS. I had complete new ac system put in just a few months ago. It does work-compressor kicking in, but I'm get'n a mix of warm air from heater core. Temp selector is on cold, blue. Guy told me the door is not closing to keep hot air trapped. He has had some major medical issues since put'n unit in, so I have to try to fix myself.
Electronic controlled?
Location of switch, solenoid that I need to change?
Or ???
Thanks............

 

I'm having the same problem in my 1996 Olds Bravada, so i thought I'd do some research for both of us.

The system is electrically operated. Check the control assembly in the dash. It's held in by four screws. Remove the dash bezel first, then the 4 screws and pull out the control unit. Make sure it's all plugged in and the wires haven't been chewed by wildlife.

In the drawings in the GM parts catalog, The electrical actuator looks like it is on top of the heater case deep in the dash. It's widely available, which says to me that it's a problem part. GM Part # 89018356, AC/Delco part # 1571845, and it's even available from Dorman as Dorman part # 604100.

There are several 'how to' videos on YouTube. Here's one that might help: He shows a special flex head ratchet in that one which would be handy for reaching the screws/bolts without taking out the dash.

I seem to remember the blend door itself being a potential problem as well. That's also deep in the heater core case. If that's broken, you're up a creek without apart. The GM part # is 52472798, but it's discontinued and no longer available. I don't see a cross reference for any after-market versions, either.

 

Thanks Racer_X for your help. I'll be checking out you tube.