Control Assembly: Description and Operation

With the ignition switch in the ON position, voltage is supplied through the HVAC fuse and circuit 41 (B RN) to the heater-A/C control assembly. The voltage from circuit 1199 (DK BLU) is varied from B+ to approximately 1.5V by the temperature control potentiometer. The heater-A/C control receives ground from G200 through circuit 1450 (BLK).

Air Delivery

Control of air through the system is regulated by vacuum. At various positions on the heater-A/C control assembly, mode control valves mix and direct cooled, heated and outside air through the air ducts.