Chrysler Repair: 1990 Chrylser Lebaron Panel Heater Controls, 1990 chrysler lebaron, air distribution system

Question
I have a 1990 Chrysler Lebaron Convertible V6 and I have no heat or air coming out of the Vents, only from the defroster by the window. When I push the control buttons on the panel to switch it from Floor to Panel to Bi Level it has no effect. I checked the fuses and they all look good. Any idea what the problem could be. It was working great and I have made no modifications or repairs to the car.

Answer
Hi Heide,
The air distribution system is powered by engine vacuum created in the intake manifold when the engine is running. If you look under the hood at the large power brake canister at the firewall right in front of the driver position you will see a large rubber hose coming from the engine to the canister. Then look near the connection of the hose to the canister for a very thin translucent hose  (or it might be black but in any case thin) that branches off the big hose and is routed behind the engine to about the midline of the body where it passes thru a hole in the firewall to enter the cabin where it is attached to the vacuum valve that operates the air distribution system. Look at its connection to the big hose and along the hose to make sure it is not disconnected from the big hose or cracked. If it seems to be o.k. on the engine compartment side of the firewall then you have to look along the passenger side of the console in the cabin at the height of the ventilation controls for the other end of the thin line and make sure that it is attached to a small check valve and thence to the vacuum control valve. You might have to remove the control unit from the center console to prove that out. Somewhere from the big hose in the engine compartment to the control valve in the center console for the air distribution system there is a leak in that thin vacuum line, which once corrected will restore the ability to direct the warm air wherever you want it to go.
Roland