Automatic Temperature Control

CIRCUIT OPERATION
Power for the ATC power module, and the blower motor, is supplied on circuit C1. This circuit is protected by a 25 Amp fuse located in cavity 21 of the junction block. Power for the fuse is supplied on circuit A22 from the ignition switch. This circuit is HOT in the RUN position only.

Power for the A22 circuit is supplied by circuit A2 from the Power Distribution Center (PDC). The A2 circuit is protected by a 40 Amp fuse located in cavity J of the PDC.

Ground for the power module is supplied on circuit Z1. This circuit terminates at the Airbag Control Module (ACM) bracket.

Circuit C56 is used for blower motor speed control. This circuit connects from the Body Control Module (BCM) to the power module.

Blower motor speed is determined by the BCM based on the position of the fan switch located in the control head.