ac blower probs

[dbland]

I have a 95 yukon. AC works buts does not blow out of the top vents, only on your feet. Are these controlled by cables that pull them open or is it a hose?

 

[Bob Urban]

Pretty sure they are controlled by vacum and I have no clue how to fix it?

 

[haks310]

Are the feet vents the only ones that work?

The knob connects to a rod behind the AC panel which turns according to the vent selection. Knob might have came loose from the rod. Basically the knob might be spinning but the rod is not, so it is stuck in the feet vent position.