So, I just got my Cutlass, and I'm having an issue with the ventilation system - nothing comes out, even when the thing is set to "vent" and it's blowing full blast. It's an A/C car, whose A/C works as far as I know (I've turned it on a coule times, the clutch spins and the engine idle lowers, but I don't plan on running it till the system gets checked out by a professional) - but as far as fresh air from outside goes, what could be blocking it? Is there a cable or something I can check the operation of?Furthermore, can anyone point me to a body manual (which may have this information) at a reasonable price?

 

Sounds like the vacuum motors are not opening and closing the dampers inside the plenum box.
The dampers can be moved by hand. If moving them gets air to flow, then:

Look under the dash at the hoses going from the little diaphragms to the control panel. Check for loose or cracked or split hoses.
Also check the main hose coming from the vacuum can on the firewall going to the control panel.
If all the hoses are good, then the control panel may be bad.

You will need the chassis manual to a accurately dignose the problem; they are available at all the popular online parts vendors.