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 this air. The air travels to the passenger compartment via ducts and outlets.
The heater control unit allows the operator to operate the heater and ventilation system. The heater control unit has 4 levers that control the temperature, the mode, the blower speed, and the fresh/recirc settings.
The temperature lever controls the temperature of the air delivered to the passenger compartment. This lever opens and closes the air mix door, controlling the amount of air which passes through and around the heater core.
The mode lever allows the driver to select the following air outlets:
| • | Ventilation (center/side IP vents) |
| • | Bi-level |
| • | Heat (floor) |
| • | Heat and defroster mix |
| • | Defroster |
The blower speed lever controls a 4-speed blower motor and fan. The blower speed lever allows the driver to regulate the amount of the air, cold or warm, delivered to the passenger compartment.
The fresh/recirc lever controls the air inlet of the blower. In recirculate mode, the blower sends inside air from the passenger compartment through the heater system and back into the passenger compartment. Recirculate mode heats the passenger compartment faster. During normal heater operation, use the fresh mode in order to prevent window fogging. In the fresh mode, the blower sends outside air through the heater system and into the passenger compartment.
