A/C Heat Valve

The A/C-Heat Valve Vacuum Actuator, which controls the A/C-Heat Valve, is bi-directional. The actuator is operated by two bellows and two vacuum switches. With the Mode Selector in MAX, NORM or VENT, vacuum is applied through the YELLOW hose. The bellows closest to the YELLOW hose contract pulling the A/C- Heat Valve to position A. Air flow is directed to the Instrument Panel Outlets with some air bleed to the Floor, Windshield and Side Window Outlets.

The A/C-Heat Valve Vacuum Actuator has vacuum applied through the RED hose with the Mode Selector in OFF, HTR, or DEF. The bellows closest to the RED hose contract. The A/C-Heat Valve is pulled to position C. All air is directed to the Floor, Windshield or Side Window Outlets depending on mode selector position.

With the Mode Selector in B/L (position 4), no vacuum is applied to either side of the A/C-Heat Valve Vacuum Actuator. Both bellows extend partway. The A/C-Heat Valve moves to position B. Air flows out of the Instrument Panel, Floor and Side Window Air Outlets, with some air bleed to the Windshield Air Outlets.