Need help with a part for a 1997 Ford E350 6.8L triton V10, A/C vacuum control valve. what does it do?

I think that it is bad because when i turn the knob on my a/c to the dash level vents it just comes out the vents on the dash and on the floor, i just replaced all of the bad vacuum line and im still having this problem. could this be the cause and how can i tell if its bad? also please list any other parts store parts numbers that you can find.





Thank youNeed help with a part for a 1997 Ford E350 6.8L triton V10, A/C vacuum control valve. what does it do?
It could be the switch but usually just the vacuum lines go bad. could just be the flaps sticking check them out try to move them by hand and lube em up a little