Buick 2010 Lucerne - Manual (Page 187)

Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog or frost from the rear window.
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(Rear Defogger): Press to turn the rear window
defogger on or off. An indicator light below the button
comes on to show that the rear window defogger is on.
Be sure to clear as much snow from the rear window as
possible.
The rear window defogger only works when the ignition
is in ON/RUN. The rear window defogger stays on for
about 20 minutes after the button is pressed if the
vehicle is traveling at slower vehicle speeds. At higher
vehicle speeds the rear window defogger may stay on
continuously. If turned on again, the defogger only runs
for about 10 minutes before turning off. The defogger
can be turned off by pressing the button again, by
turning the ignition to ACC/ACCESSORY or ON/RUN,
or by turning off the engine.
The heated outside rearview mirrors will heat to help
clear fog or frost from the surface of the mirror when the
rear window defogger is on. See Outside Heated
Mirrors on page 3‑36 for more information.
Notice: Do not use a razor blade or sharp object to
clear the inside rear window. Do not adhere
anything to the defogger grid lines in the rear glass.
These actions may damage the rear defogger.
Repairs would not be covered by your warranty.
Outlet Adjustment
Use the levers, located in the middle of the front
outlets, to change the direction of the airflow. Use the
thumbwheel located between the outlets to turn them on
and off.
If the vehicle has rear seat outlets, adjust the direction
of the airflow using the lever in the center of each outlet.
Operation Tips
. Clear away any ice, snow, or leaves from the air
inlets at the base of the windshield that could block
the flow of air into the vehicle.
. Use of non-GM approved hood deflectors can
adversely affect the performance of the system.
. Keep the path under the front seats clear of
objects to help circulate the air inside the vehicle
better.
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