LOWER
The air inlet valve is in the outside air position when the following conditions are present:^ Vacuum is supplied only to the defrost and A/C valve actuator.
^ All of the other actuators vent.
The blower pulls outside air into the system. The air is heated or cooled. The air is then forced through the floor outlets.
The temperature control circuitry activates so that the temperature knob can adjust the discharge air temperature.