With Dual Zone A/C (CJ2)

MODE SELECTOR BUTTONS
The mode selector buttons utilized by the Buick control head are AUTO, AIR FLOW (up down rocker switch), VENT, RECIRC, FRONT, DEFROST and REAR DEFOG.
Pressing AUTO tells the HVAC programmer to set the air intake point, air discharge points and activate or de-activate the A/C compressor, according to the operator selected SET temperature and information provided by the system's network of sensors.

"AIR FLOW" BUTTON
The "AIR FLOW" button is used to change the air flow direction in the vehicle. Selection of the "AIR FLOW" button when in AUTO" mode will lock in the air flow direction that "AUTO" was controlling and in not active, activate the VF display for that direction. If an air flow direction is being displayed the next air flow direction will be selected either up or down depending on operator selection. The air flow direction will sequence upward through the following modes:
- "FLOOR."
- "FLOOR/MID."
- "MID".
- "WINDSHIELD/FLOOR."
The downward sequence will be in reverse of the upward. These will be the only air flow directions available by the "AIR FLOW' 'button.

"VENT"
This button is used to toggle on or off any request for compressor operation. When the switch is activated the "VENT" LED will light and the system will request that the A/C compressor be turned off. "VENT" and "RECIRC" can never both be enabled at the same time. If "VENT" is enabled, selecting "RECIRC" will cancel "VENT". If "RECIRC" is enabled, selecting
"VENT" will cancel "RECIRC." This button will have no effect on the system when "FRONT DEFROST" mode is selected.

"RECIRC"
This button is used to activate the recirc door. When the switch is activated, the "RECIRC" LED will light and the system will request that the recirc door close. The main function is to limit the amount of outside air that is brought into the vehicle. "VENT" and "RECIRC" can never be enabled at the same time. If "VENT" is enabled selecting "RECIRC" will cancel "VENT." If "RECIRC" is enabled selecting "VENT" will cancel "RECIRC." This button will have no affect on the system when "FRONT DEFROST" mode is selected.
When the "RECIRC" mode is active, any manual mode change will cancel the "RECIRC" function.
Once activated the "RECIRC" function will operate for a period of ten minutes. After the ten minutes the function is automatically canceled.

"FRONT" DEFROST BUTTON
When the "FRONT" Defrost button is pressed the LED in the switch is illuminated and the SET temperature is displayed for five seconds. The "FRONT" Defrost button sends a message to the programmer which results in air being directed to the windshield. This is a manual only mode.