Vacuum Control Motors

WARNING: This page is about a different car, the 2004 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

The vacuum control motors (18A318):

Are located on the A/C evaporator housing, A/C recirculating air duct (19C590) and heater air plenum chamber (18471).
Direct system airflow to the vehicle interior as determined by the function selector switch.