Buick 1994 LeSabre Owner's Manual page 128

Air entering the car will be evenly split between the
floor outlets and the outlets near the windshield.
The blower speed will be controlled automatically.
You
can choose another fan speed by pushing the HI or LO
buttons.
Defrost
This setting directs most of
the air flow toward the
windshield. Use this when
there is fog or ice on the
windshield.
Defrost will work better if any ice and snow is cleared
from the hood and the air inlet area between the hood
and the windshield.
Blower speed will be controlled automatically. You can
choose another speed by pushing the HI or LO buttons.
Rear Window Defogger (Option)
The
lines
you see
on the
rear window warm the
glass. Press the button to
start warming your
window.
After 10 minutes, it will go off by itself or, pressing the
button again during the heating cycle will shut it off. If
you need additional warming time, push the button again.
If you have the heated outside rearview mirror option,
the mirror will be warmed when the rear defogger is on.
I
NOTICE:
Scraping the inside of your rear window could
cut and damage the heater. Your warranty would
not cover this damage. Don't put decals there,
you might have to scrape them off.
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