Lexus 2004 GX470 Owner's Manual page 247

AIR CONDITIONING
REAR COOLER CONTROLS
21PY034
"
1 Rear cooler vents
2 Fan speed control button
3 "REAR COOL" button
4 Temperature control button
232
(a) Rear cooler ON-OFF
To turn the rear cooler on, push the "REAR COOL" button
with front air conditioning on. To turn the rear cooler off,
push the button once again.
When you turn the rear cooler on with the front air conditioning
off, the cooling device is not operated.
(b) Air flow control
The fan speed can be set to your desired speed by pushing
the appropriate side of the fan speed control button.
"AUTO" mode: The fan speed is automatically adjusted only
when the air flow setting of the front air conditioning is in the
panel mode.
(c) Temperature control