Operation CHARM: Car repair manuals for everyone.

Air Temperature Actuators

The vehicle operator can determine the temperature of the A/C air by using the air temperature switch. When a desired temperature setting is selected, a voltage divider is used to determine the air temperature door position signal circuit's value. The air temperature door position signal circuit's value is a voltage that is applied to the air temperature actuator. The motor opens the air mixture door to a position to divert sufficient air past the evaporator or heater core to achieve the desired vehicle temperature. Warm heater air is mixed with cool A/C air at the air mixture door When the coldest temperature control setting is selected, no warm heater air is mixed with the cool A/C air.