Control Components

There are four different heating and cooling options.The four climate control assemblies are:
^ Manual front with heat only
^ Manual front with A/C and heat
^ Manual front and rear with A/C and heat
^ Electronic Automatic Temperature Control (EATC)

Manual A/C
The manual climate control system heats or cools the vehicle interior depending on the function selector position and the temperature selected. The function selector position determines heating or cooling and air distribution. The temperature blend control setting determines air temperature.

The manual climate control components are used to:
^ select air inlet source (outside or recirculated).
^ select blower motor speed.
^ select discharge air temperature (temperature blend).
^ select discharge air location (defrost, panel, floor).
^ select A/C compressor clutch operation.

Electronic Automatic Temperature Control
With the use of a microcontroller, the electronic automatic temperature control (EATC) module analyzes input from the following major sources:
^ temperature, function and blower selection (made by the vehicle occupants)
^ in-vehicle temperature
^ ambient temperature
^ sunload
^ vehicle speed
^ engine coolant temperature

Using these inputs, the microcontroller determines the correct conditions for the following outputs:
^ A/C compressor clutch engagement
^ blower speed
^ air temperature blend door position
^ panel/floor door position
^ panel/defrost door position
^ air inlet duct door position
^ outside temperature display

Temperature Control - Manual
Temperature control of the heating and defrosting system is determined by the position of the temperature control knob. Cooler temperatures are achieved by rotating the knob counterclockwise. Warmer temperatures occur when the control knob is rotated clockwise. The temperature control switch can be replaced separately from the manual control assembly.

Temperature Control - Electronic Automatic Temperature Control (EATC)
Temperature control of the electronic heating and defrosting system is determined by the TEMP button. Depressing the button will show and set selected temperature in the display window. Push the left side of the button to lower the temperature setting. Push the right side of the button to raise the temperature.

Blower Motor Control - Manual Control System
The position of the blower motor control knob determines the speed at which the blower motor operates. Each position of the blower motor control knob is detented for positive engagement. The blower motor control works in conjunction with the blower motor resistor to control the four-speed operation of the blower motor. The blower motor control switch can be replaced separately from the manual control assembly.

Blower Motor Control - Electronic Control System
The rotation of the blower motor control determines the speed of the blower motor. The blower motor control works in conjunction with the A/C blower motor speed control to control the 12-speed operation of the blower motor.

Blower Motor
The blower motor is mounted within the A/C evaporator/blower motor assembly, and contains the following:
^ blower motor and blower motor wheel
^ blower motor resistor (with manual control option)
^ A/C blower motor speed control (with electronic control option)
^ A/C air inlet door
^ A/C air inlet door actuator motor
^ A/C evaporator core (if equipped)

Blower Motor Resistor
The four-speed operation of the blower motor is achieved through the blower motor resistor. The blower motor resistor is mounted under the A/C evaporator/blower motor assembly.