air flow in cabin not working

Those doors are controlled by vacuum. Check for leaks and cracked hoses. You may just want to replace the hose from the engine to HVAC control panel without looking for leaks - it's cheap and probably in that section anyway.

As tenspeed stated its probably a vacuum issue. Mid 80 chevy cars have a vacuum deverter valve right on the back of the control panel. It has I believe five out going vacuum lines hooked to it. It controls the flaps according to what you have the control panel set to do.(defrost, heat, ect. ). These tend to go out as they get old. If you have good vacuum going to it but none coming out to control the flaps I would look into replacing it.. Hope this helps

Thanks for pointing me in the right direction. The cog that rotates the vacuum and control arm together was not set. When I would move the control arm from AC to vent to heat it was not turning the vacuum controller. Once I set it correctly the AC is now blowing correctly.

Before adjustment

My blower motor is new but won't work when plugged up properly, same as well with my air compressor. The clutch clicks on and works fine if i run power to it but not when hooked up correctly. I've checked and replaced the dash unit above radio and checked all fuses, do you know or help me out with my problem please?

Mine is an 89 Chevy caprice