Why won't air won't come out my car's front air vent's? ?

Question

I have an 00' Yukon, i put the a/c on full blasts air come out but only through the windshield, floor and rear roof vents, but not through the front ones. Can somebody help me.

Answer 1

Sometimes I find I have my dash control vent k**b in the wrong position.  Restudy your owner's service manual.

Answer 2

You may have a loose vacuum hose under the dash. The vent doors are opened and closed by vacuum. Have someone listen under the dash as you operate the vent controls. If you don't hear the door open or shut when you change the control, it's probably a vacuum hose.

Good luck.