A/C works but...

I did a search and could not find what I was looking for. My A/C is working, but it will not blow out of the dash vents, only the heater vents on the floor. I think its some kind of vaccum leak. Any suggestions??

Come on guys it's hot as hell up here.

The only thing I can think of is a vacuum problem or a linkage problem as something is not changing the vents to the proper configuration.

Remove the cover on the vents for the foot area, stick your hand in it and you will feel the diverter door.
See if it moves when you change the controls.
I have seen these break off the little tabs that hold them in. The part is not expensive, but the whole dash needs to be removed to replace it..

Hope this helps.