Vacuum Motor

This is a single acting diaphragm type unit with the vacuum motor mechanism (stem) spring-loaded so that the stem will be fully extended without vacuum and will be pulled into the motor as vacuum is applied. Vacuum motor performs a number of operations as follows: 1) Rotates output shaft linked to air mix door to provide progressive movement of the door from heating to air conditioning position, 2) Operates rotary vacuum valve to control operation of all vacuum diaphragms in conjunction with control head vacuum valve, 3) Operates blower switch to provide correct blower speed (Low, M1, M2, Hi) for each phase of operation, and 4) Operates feedback potentiometer through a gear drive.