Control Assembly: Description and Operation
Manual A/CPower is applied to the heater control panel, mode control, and recirculation control motors through fuse 19 when the ignition switch is in the ON (II) position.
The heater control panel and mode control motors are grounded at G303.
As you press each mode button on the heater control panel display, a corresponding LED will illuminate, indicating the air delivery mode selected.
Each button provides a path to ground for specific outputs from the mode control motor. The motor varies the position of the heater-evaporator door to control the air flow direction and volume.
The fresh and recirculation buttons on the control panel control the recirculation control motor which regulates the positioning of the Fresh/Recirc door.
The air mix control motor is powered by 5V from the temperature control output of the heater control panel; it is grounded through the heater control panel at G303.
The air mix control motor is controlled by three output signals from the heater control panel.
Climate Control
The climate control unit receives battery voltage at all times through fuse 56. With the ignition switch in ON (II), voltage is supplied to the climate control unit. The control unit is grounded at G303.
The climate control unit controls the air delivery motors, and supplies a 5VDC reference voltage to the air mix and mode control motors.
The air mix and mode control motors each receive three inputs from the climate control unit. 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. 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 at the (sensor ground) of the climate control unit.
The recirculation control motor receives battery voltage through fuse 19 when the ignition switch is in ON (II).
The recirculation control motor regulates the position of the fresh/recirc door. The motor is controlled by two position inputs from the climate control unit ("Recirc" and "Fresh").