Heating system on 99 ranger

[Frank-O]

Hey All,
One more brain buster for you all here. MY heater, and air conditioning work, but it only blows out teh top near the windshield. Air does not come out any of the other ports, no matter where my heater knob is located. So basically, I have a constant flow of defrost, but nothing else.
Any ideas?
Frank-O

[rivguy]

you have a vacume leak between the engine and heater control head