My 98 ZX2 all of a sudden decided it no longer wanted to shoot the AC or heat out of the dash vents? All the other vents work the windshield and floor are now the only place the heat or AC comes out of? Anybody have any suggestions?
The default for all vehciles, is for the air flow to come out of the defrost ducts ( with some leakage to the floor) if there is a malfunction. Is that what it is doing? do you have cold air coming out of the defrost duct? The blend doors and mode doors are controlled by electrical or vacuum motors when you press the buttons. Does the heat/cold blend door change the temp when you move it?
Do you hear any of the other mode doors move whne you press the other switches? I would suspect it's the heater/a/c control head (with all the buttons). good luck.