Dodge 2009 Challenger Owner's Manual page 237

NOTE:
The feature can be disable by parking the vehicle with
the blower control set to the "O" (or OFF) position.
For maximum performance, it is recommended that
the vehicle is parked with the blower control set to the
"High" (full clockwise) position.
Operating Tips
NOTE: Refer to the chart at the end of this section for
suggested control settings for various weather condi-
tions.
Summer Operation
The engine cooling system in air-conditioned vehicles
must be protected with a high-quality antifreeze coolant
to provide proper corrosion protection and to protect
against engine overheating. A solution of 50% ethylene
glycol antifreeze coolant and 50% water is recommended.
Refer to "Maintenance Procedures" in Section 7 of this
manual for proper coolant selection.
UNDERSTANDING YOUR INSTRUMENT PANEL 235
Winter Operation
Use of the air Recirculation mode during winter months
is not recommended because it may cause window
fogging.
Vacation Storage
Anytime you store your vehicle, or keep it out of service
(i.e., vacation) for two weeks or more, run the air
conditioning system at idle for about five minutes in the
fresh air and high blower settings. This will ensure
adequate system lubrication to minimize the possibility
of compressor damage when the system is started again.
Window Fogging
Interior fogging on the windshield can be quickly re-
moved by turning the mode selector to Defrost. The
Defrost/Floor mode can be used to maintain a clear
windshield and provide sufficient heating. If side win-
dow fogging becomes a problem, increase blower speed.
Vehicle windows tend to fog on the inside in mild but
rainy or humid weather.
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