For 1990-2009 cars

### Heater Hoses

The heater hoses carry the engine coolant from the engine to the heater core. The heater hoses attach to the following locations:

• | The heater core at the front of the dash

• | The inlet pipes at the engine

• | The outlet pipes at the engine

### 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.