Air Flows From Wrong Outlets
WARNING: This page is about a different car, the 1995 Ford Pickup, 1995 Ford F-Super Duty, 1995 Ford Cab & Chassis, and 1995 Ford Bronco. However, it is still accessible from the selected car via links, so may be relevant.
Test vacuum check valve. Check for vacuum leaks and inoperative vacuum motor. Check for correct vacuum hose routing.