I have no air coming out of my dash vents in response to button selections. Air only blows from defrost and/or floor. Air is plenty cold/hot, just doesn't blow from the dash vents when 'auto' is selected or if I choose dash air. Is some door stuck? Something I can spray WD40 on?
Sounds like you have a vacuum line off or a vacuum leak, check around the controller and the blend doors under the dash, access may be fairly restricted, if in doubt get a mechanic to test the system, I will look at the systematic and if there is any obvious point that may be a concern I will post it soon.