Heat on - no vent air in cabin

[RGW1917]

I'm a new member and new Taurus owner. Bought a 99 Taurus Wagon with 103,000 miles on it. Very clean and well maintained; was a Minnesota state-owned vehicle. Runs great; very quiet. Problem is that unable to control the heat - it's either on or off - if I switch to manual and try and turn the heat down, it doesn't change - just hot air. When switch to vent, it still just blows hot air (have to open windows). I am able to hit the "off" button and shut it off entirely - sometimes it's nice to have just a bit of heat, though. When turned the air conditioner on, still heat (although my brother was able to verify that the air conditioner compresser works). My brother thought he could clamp a hose and stop the heat, but I guess I'd like a better option, such as knowing what the problem might be and how to fix it. Also, I will want air conditioning this summer. Thanks in advance for options to try and your ideas.

[phantom_smack]

Sounds like the blend door motor is bad or the blend door itself is broken.I believe you can access the blend door without removing the dash its the motor over the heater core access cover but I'm not 100%.I will try to look it up in a bit the Ford site is down .anyone know for sure?

[phantoms]

Check your fuses. I had the same problem with my T-Bird. Heat never shut off. The fan just kept blowing hot air. As it turned out the problem was a Run fuse that was bad. Replaced it and the everything went back to normal. Give that a shot and see if that is your problem.