1998 Ford Contour • 4 cylinder 2WD Automatic • 200,000 miles

No air will come out of any vent om my Contour. Nothing from defrost, vents or on the floor. I can hear the fan blowing air and when I removed the glove compartment and manually moved the arm I was able to get air to the defroster. But as soon as I let go of the arm, it returns to the closed position.
I've removed the center panel and looked behind the selector. When I removed the vacuum hose connected to the back of the connector I feel no air or vacuum, even if I put my thumb on it and cover all ports.

What can I do to fix it?

Thank you

May 31, 2011.

Trace the white vacuum line (I believe it's white) from the switch through the firewall to the engine it's probably broke somewhere

Jun 1, 2011.
The vent doors are actuated by vacuum. Follow the supply hose to the engine (through the firewall). Chances are the plastic hose is cracked or melted.