Lexus GS300 1998 Owner's Manual page 217

AIR CONDITIONING AND AUDIO
20G007
To remove interior fog on the windshield –
Push the"FRONT WINDSHIELD" button.
To remove frost or exterior fog on the windshield –
1. Place the temperature control button at the maximum
temperature.
2. Push the "FRONT WINDSHIELD" button.
3. Push the fan speed control button on the right side to obtain
a maximum air flow.
4. Leave the air conditioning on–off button off.
204
When the "FRONT WINDSHIELD" button is pushed while
operating in automatic mode, the air conditioning is set to
operate and the OUTSIDE AIR mode is set.
If you push the "FRONT WINDSHIELD" button once again
while in the FRONT WINDSHIELD mode, the mode then
returns to the last mode used.