Control Components

Component Locations, Part 1:

Component Locations, Part 2:

The manual climate control system heats or cools the vehicle interior depending on the function selector position and the temperature selected. 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.

Climate Control Assembly
The climate control assembly has three system controls:
^ The A/C heater function selector switch combines a vacuum selector valve with two electrical switches to supply battery positive voltage to the A/C clutch circuit and the blower motor control circuit.
^ The temperature selection is accomplished with a potentiometer connected to the electric blend door actuator that controls positioning of the temperature blend door. Movement of the control knob from COOL (Blue) to WARM (Red) causes a corresponding movement on the air temperature control door and determines the temperature that the system will maintain.
^ The blower motor switch controls blower motor speed by adding or bypassing resistors in the heater blower motor switch resistor.

Blower Motor Resistor Coils:

Blower Motor Thermal Limiter:

Blower Switch Resistor
The heater blower motor switch resistor has the following features:
^ The assembly is located on the passenger side of the vehicle on the evaporator housing.
^ Three resistance elements are mounted on the resistor board to provide four A/C blower motor speeds.
^ Depending on the heater blower motor switch position, series resistance is added or bypassed in the A/C blower motor circuit to decrease or increase A/C blower motor speed.
^ An overheating protective device (thermal limiter) will open the resistor coil circuit when the temperature reaches 121°C (250°F) interrupting the blower motor operation in all speeds except HI.
^ The thermal limiter cannot be reset and is not serviceable.