Chrysler Repair: 94 Lebaron: heater air distribution problem, power brake booster, air doors

Question
Heater and A/C blow air to the defrost and feet regardless of the position selected.

Answer
Hi Jim,
The air distribution doors are operated via the vacuum created in the engine's intake manifold. There is a thin vacuum line that branches off from the power brake booster and is routed through a small hole in the firewall, about mid-line of the body. Find that line and check to make sure that it is attached to the booster and is not broken or cracked. If that seems OK then check under the dash where you will find that it comes to the heater/ac control panel mode switch. It also has a check valve in the line which if stuck open would cause the air doors to shift around when you step on the gas instead of holding their position. Also, check the bigger vacuum hose that comes from the intake manifold to the booster to be sure its clamps on either end are tight.
Then if that doesn't do it, let me know and we can go further.
Roland
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