Operation CHARM: Car repair manuals for everyone.

Heater Control Assembly

The base heater system consists of the following 5 modes:
^ Vent
^ Heat
^ Defrost
^ Bi-Level
^ Blend

The following functional assemblies control the base heater system modes within the heater module:
^ The motor and fan assembly (blower) provides the air flow from the air inlet. The blower regulates the air flow for further processing and distribution.
^ The heater core transfers heat from the engine coolant to the inlet air. This transfer heats the inlet air.
^ The temperature valve regulates the amount of air that passes through the heater core. The valve controls following items:
- The temperature
- The mix of heated and ambient air.
^ The following valves regulate the flow and distribution of processed air to the distribution ducts:
- The mode valves
- The defrost valves
- The heat valves

The following components control the operation of these assemblies on the control assembly:
^ The levers
^ The switch

The temperature knob operates an electrical actuator that opens and closes the temperature valve. The mode lever operates a vacuum control in order to select the appropriate mode.