Heating System Circuits

The heater control panel receives battery voltage at all times through fuse 13. With the ignition switch ON (II), voltage is supplied to the control panel through fuse 3. The control panel is grounded at G401. It controls the blower motor, and supplies a 5 VDC reference voltage to the air mixture control motor.

The air mix and mode control motors each receive inputs from the control panel. The air mix motor regulates the mixture of cold and hot air by varying the position of the heater-evaporator door. The mode control motor controls the direction and volume of outlet air. The air flow can be directed to the dashboard vents or the corner vents. Both the air mix control motor and mode control motor are grounded by the control panel.

The recirculation control motor receives battery voltage through fuse 3 when the ignition switch is ON (II). It regulates the position of the fresh/recirc door, and is controlled by two position inputs from the control panel ("Recirc" and "Fresh").