Controls

Control Assembly:

PURPOSE
The control assembly in the instrument panel contains three rotary control knobs: blower speed, mode selection, and temperature adjustment. Brightness of the dial illumination is controlled by the instrument panel dimmer control.

COMPONENTS
Temperature Rotary Knob
When the temperature rotary knob is in the full "COLD" or counter clockwise position, all of the air delivered by the ventilation system is unheated. When the temperature rotary control is in the full "HOT" or clockwise position, all of the air passing through the heater module is heated before it is discharged. intermediate positions of the temperature rotary knob result in a mixture of heated and unheated air to provide more moderate air temperatures.

Mode Rotary Knob
The mode rotary knob operates the defrost control cable that goes to the left end of the heater module. This cable operates a crank lever and shaft that controls the position of an air valve in the heater module. There are detents at 0°, 90°, and 180° to indicate VENT, FLOOR, and DEFROST mode positions. Air delivery may be blended by placing the rotary control anywhere in between the two desired modes.


Bower Speed Control
The blower switch provides a choice of four blower speeds and off. It receives power through the HTR-A/C FUSE when the ignition is "ON." in the "LO" position, the circuit continues through the heater wiring harness to two resistors in the resistor assembly near the blower motor.

When the blower switch is in a medium-speed position, the circuit continues through the heater wiring harness to the resistor assembly, but it bypasses one of the two resistors. When the blower switch is in the "HIGH" position, the circuit continues through the heater wiring harness to the resistor assembly, but it bypasses both resistors to provide full power to the blower motor.

From the resistor assembly, the circuit goes to the blower motor terminal to operate the blower motor. The blower motor circuit is completed to ground by a sheet metal ground wire that connects to a ground terminal on the cowl.