For 1990-2009 cars

The heater system delivers warm air to the passenger compartment after the engine reaches normal operating temperature. Outside air and air from the passenger compartment pass through the heater core. Hot engine coolant heats the air, which travels to the passenger compartment through ducts and outlets.

The heater control unit allows the operator to operate the heater and ventilation system. Four levers are provided for control of the following heater operations:

• | The temperature lever

- | The temperature lever controls the temperature of the air delivered to the passenger compartment.

- | The lever opens and closes the air mix door, which controls the amount of air passing through and around the heater core.

• | The mode lever

| The mode lever allows the driver to select from the following choices of air output:

- | Ventilation

- | Bi-level

- | Floor heat

- | Heat and defroster

- | Defroster

• | The blower speed lever

- | The blower speed lever controls a four-speed blower motor and fan.

- | The blower speed lever allows the driver to regulate the amount of cold or warm air delivered to the passenger compartment.

• | The fresh/recirc settings lever

- | The fresh/recirc lever controls the air inlet of the blower.

- | In the fresh mode, the blower circulates outside air through the heater system.

- | In recirculation mode, the blower circulates inside air through the heater system.

- | Recirculated air heats the passenger compartment faster than fresh air.

- | Use fresh air during normal heating operation in order to prevent window fogging.