Heater-A/C Control

With the ignition switch in the RUN position, voltage is applied to the heater-A/C control through the HVAC/DRL Fuse (circuit 241) in the fuse block. The RADIO Fuse (circuit 640) in the underhood accessory wiring junction block provides voltage to the heater-A/C control at all times. The voltage from circuit 241 is varied from battery voltage to approximately 1.5 volts by the temperature control potentiometer. The heater-A/C control provides a ground from G200 through circuit 150. Control of air through the system is regulated by vacuum. At various positions on the control, mode valves mix and direct cooled, heated, and outside air through the air ducts.

The electric slave actuator receives voltage at all times through circuit 241 from the HVAC/DRL Fuse in the fuse block. It also receives ground from G200 through circuit 150. The heater-A/C control sends a signal through circuit 733 to the electric slave actuator that is determined by the position of the temperature control. This signal is used by the electric slave actuator to determine the position of the temperature door.

The electric air inlet actuator receives voltage at all times through circuit 241 from the HVAC/DRL Fuse in the fuse block. It also receives ground from G200 through circuit 150. The heater-A/C control sends a signal through circuit 684 to the electric air inlet actuator that is determined by the position of the air recirculation switch. This signal is used by the electric air inlet actuator to determine the position of the air inlet door as to whether outside or inside air is circulated.