Auto Air Conditioning & Heater Repair: 1990 Corvette, ventilation ducting, diaghram

Question
I own a 1990 Corvette and the air conditioning doesn't blow out the vents on the dash,only on the defroster vents and the ones on the floor. Before I start to take my dash apart,can you give me some ideas. Thanks Steve

Answer
Steve,
First off, Nice ride.
It sounds as though the door actuator for the dash ventilation ducting may have gone bad on you. Does it blow at all through them? Even a little bit?
If not, then I would safely conclude that the actuator is your issue. The default position for the dash doors are closed. They will only open when a vaccuum is pulled on the actuator that operates them.Either your actuator diaghram is bad and the whole component needs replaced, or the vaccuum line that operates it has come off. Do you hear a pronounced hissing sound coming from the passenger floorboard area when you set it to the dash vents? If so, you lucked out and your line just needs to be put back on it. If not... you are looking at about a 250-400 dollar job (all inclusive) to have it repaired.
I hope this answer helps you out a bit. If I can do anything further either now or inthe future, please do not hesitate to ask. If you found this answer at all helpful, please remember to rate it. Thank you for your question and good luck in everything.