I own a 1991 Chevy Corsica and I can't hardly get any air flow through the vents with the fan on high. The vent selector works and hardly any air comes out of the defroster and hate how long it takes to heat car. What is wrong?
this sounds like a leaky or disconnected vacuum line, and prolly under the hood. all the vent and heater and a/c doors are operated by acuaros and they open and close to let in the air to whichever you have the set control moved to,,such as,,floor, defrost, vent, floor and front vents...etc. they're all operated by vacuum, so look under the hood first for a vacuum line running thru the firewall....definetly a hose leak