For 1990-2009 cars

### A/C Switch

The A/C switch controls the operation of the air conditioning system. The A/C switch is mounted on the heater control unit. In all modes, the A/C switch must be in the ON in order to engage the compressor. When the A/C switch is pressed, the switch signals the A/C compressor control module that air conditioning system operation has been requested.

The position of the temperature control lever on the heater control unit controls the air conditioning output temperature. A cable connects the lever to the air flow door that is located in the heater case. The position of the door controls the air flow through the heater core, as the temperature control lever is moved between the full hot and full cold positions.

### Blower Speed Lever

The blower speed lever (2) regulates the amount of air delivered into the passenger compartment. The blower speed lever has 5 positions. The positions are the OFF position and speeds 1-4. The blower motor is housed in the blower case which is located behind the right side of the instrument panel.

### Temperature Lever

The temperature lever (4) controls the amount of air flow to the heater core which regulates the temperature of the air entering the passenger compartment.

When the temperature lever is moved completely to the coldest position, the air mix door closes blocking the flow of air to the heater core.

When the temperature lever is moved completely to the hottest position, the air mix door opens fully allowing the air to flow through the heater core.

Moving the temperature lever between the coldest and the hottest positions allows the operator to adjust the passenger compartment temperature to the most comfortable level.

### Fresh/Recirc Lever

The fresh/recirc lever (3) controls whether fresh outside air or recirculated passenger compartment air enters the vehicle's heater and ventilation system.

Moving the fresh/recirc lever to the recirculate position provides the quickest air delivery by closing the blower mode door. Outside air is not delivered to the passenger compartment in this position. Because the vehicle is equipped with a full-time outside air system, a small amount of outside air enters the passenger compartment regardless of control position. The recirculate mode is helpful in heating up the passenger compartment faster. During normal heater operation use the fresh mode in order to prevent window fogging.

### Mode Lever

The mode lever (1) allows the driver to route the air into the passenger compartment through different outlets. The mode lever enables the selection of the following modes:

Ventilation: Air flows from the instrument panel (IP) outlets. Air quantity is controlled by the blower speed control lever. Air quantity is also affected by vehicle speed when the fresh/recirc lever is in the FRESH position. The passenger compartment receives more air as the vehicle speed increases. The passenger compartment receives some air even if the blower speed lever is in the OFF position.
Bi-Level: Air flows from the IP outlets and from the floor outlets. Warmer air flows from the floor outlets than from the IP outlets.
Heat: Air flows from the floor outlets. A small amount of air flows from the windshield defroster outlets.
Heat/Defroster: Most of the heated air flows from the windshield defroster outlets. The remaining air flows from the side window outlets and from the floor outlets.
Defrost: Air flows from the windshield defroster outlets. A small amount of air flows from the side window outlets and from the floor outlets.