HVAC air location
Melting Slicks
Joined: Mar 2012
Posts: 2,800
Likes: 456
From: USA
hvac air
I have had that happen. There is a little plastic vacumn line on the back of the intake manifold that supplies vacumn to a manifold located inside the passenger side inner fender. Mine had several holes eaten by battery acid where it entered the firewall. The vacumn controls the different position the air blows , vents, floor or defrost etc. You can do a google search and find a lot of posts about this subject. Hope this helps. 
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
All too common but the fix isn't bad once you understand what you are dealing with. Here is a good link that describes the problem and fix.
https://www.corvetteforum.com/forums...1a147a9f73d5e8
https://www.corvetteforum.com/forums...1a147a9f73d5e8
