92 Cutlass vent problem

The air vent in my cutlass supreme s will only vent to the floor/ defroster. I have taken out the vacuum switch, but I realized that that was not the problem when I noticed vacuum was not reaching the switch. What is the cause of this problem, and where does the vacuum line for the vent lead? My service manual states nothing about this.

Common problem - the Vacuum line you are looking for is between your battery and your cruise control module (right next to the washer tank) there should be a little vacuum tee there. They factory tee breaks quite a bit and will give you the symptom you describe. If the tee is not broken, Follow the lines from the vacuum tee and make sure they are all plugged in. One should lead to the intake manifold, another should lead to the vacuum ball under your driver side fender, and the other should lead to your hvac system.

Yup that was it, thx