Air Delivery Control

When the ignition Switch is in the RUN position, battery voltage is applied to terminal 7 of the Control Switches and both the LH and RH Fresh/Recirculating Air Relays. If the Fresh/Recirculating Air Switch is not depressed (open), battery voltage is applied through the normally closed contacts (87 & 30) of the RH Fresh/Recirculating Air Relay to both Fresh/Recirculating Air Flap Door Motors and then to ground through the normally closed contacts (87a & 30) of the LH Fresh/Recirculating Air Relay. Both Motors operate and move the Fresh/Recirculating Air Flap Doors to position A, allowing fresh air to enter the blower.

When the Fresh/Recirculating Air Switch is depressed (closed), battery voltage is applied through the Switch to both the LH and RH Fresh/Recirculating Air Relay coils. Both Relays are energized. Battery voltage is then applied through the closed contacts (87 & 30) of the LH Fresh/Recirculating Air Relay to the Flap Door Motors, and to ground through the closed contacts (87a & 30) of the RH Fresh/Recirculating Air Relay. Since the voltage is now applied to the Flap Door Motors in the opposite direction, the Motors reverse direction and move the Fresh/ Recirculating Air Flap Doors to position B, allowing only recirculating air to enter the blower. Both of the Air Flap Door Motors remain energized continuously. When the Doors reach the end of their travel, the Motors stall and hold the Doors in position.