Ok Guys, I know this may be a simple one. When I turn on my A/C the air usually blows out of the main vents and the side vents. Now its only blowing out of the side vents and the defrost vents( the ones up on the dashboard that hit the front windshield). What gives? Do I have a bad valve somewhere? Thank you guys.

 

That system is automatic and delivers air when its desire (don't you just hate, when the car is trying to outsmart you? I understand outsmart Lugnut, but me?)
Anyway. Vacuum cylinders direct the air to desired outlets. When no vacuum is present, spring loaded latches direct all the air into the windshields.
Does that gives you a clue?
Look at those vacuum tee connectors in the oil filter area.

 

Ok, I checked all the vacuum connections that I can see near the oil filter. They all seem to be connected. Do you have any other ideas?

 

Are door locks working OK?
If the vacuum system hold, the next step would be control module. How big is your check book?

 

The door locks are working. The passenger door was a little slugish but it seems to have worked itself out. My check book is small. What does the control module do and how much does it cost? Possible to get a used one?

 

There are 2 vac lines going into the firewall next to the brake booster.
1 controls the doors the other the climate control. Check vacuum here. If you have a leak go inside the car and try to locate where these lines come in. Follow them to each connection and check for leaks.
If you are holding vacuum you have 2 options. 1 is to get to that piece that controls the flaps or stick a screwdriver into the center vents and help the system open them....On my 82, I left the center vents open w/ chopsticks..my new default setup was all vents open all the time...you can shut the fronts down by turning them.

 

Forgot to mention that you need to remove the dash if you want to change that nice little piece back there.