Chrysler Repair: 1990 Chrysler Le Baron Heater A/C Control Panel, air distribution system, power brake booster

Question
The A/C Hetaer control panel is not responding to the button commands. The motor goes on and the AC/Is working but not as Cold as it was. It only blows through the Defrost and Floor vents. When I hit PANEL or BI-LEVEL or Floor buttons it doesn't switch over.

What to do?  

Answer
Hi Cheddy,
The air distribution system on the standard heater/AC unit is powered by the intake manifold vacuum supply. If the vacuum line from the engine compartment cracks or disconnects from a nipple then the air distribution you describe is exactly what would be expected. If you look on the dirver's side of the engine compartment near the fire wall you will see a large hose that comes from the engine to power brake booster canister. Near the point of entry you will see a T-fitting from which a thin plastic hose originates and passes thru the fire wall about at the middle of the panel so as to go to the control panel for the heater/AC. Take a look at the plastic hose for either detachment from the T or for it being cracked anywhere that you can see it. It if looks o.k. then you will need to look for the other end of the hose where it comes to the control panel to see if you can find where the leak is occuring in the cabin. You will probably have to remove the control panel to actually inspect it, which involves removing the bezel surrounding the center console and then removing the screws that hold in the control unit. You might also be able to see it if there is a space under the unit for you to access the vacuum line.
Let me know if this is not the answer, but I think is has to be a vacuum supply to the control problem.
Roland