Dodge 2009 Ram 1500 - Manual (Page 304)

Recirculation Control
When outside air contains smoke, odors, or
high humidity, or if rapid cooling is desired,
you may wish to recirculate interior air by
pressing the RECIRCULATION control button.
Recirculation mode should only be used temporarily. The
recirculation LED will illuminate on the blower control
knob when this button is selected. Push the button a
second time to turn off the Recirculation mode LED and
allow outside air into the vehicle.
NOTE: In cold weather, use of Recirculation mode may
lead to excessive window fogging. The Recirculation
mode is not allowed in the Floor, Mix and Defrost modes
to improve window clearing operation. Recirculation will
be disabled automatically if these modes are selected.
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.
Winter Operation
To ensure the best possible heater and defroster perfor-
mance, make sure the engine cooling system is function-
ing properly and the proper amount, type, and concen-
tration of coolant is used. Refer to “Maintenance
Procedures” in section 7 of this manual for proper coolant
selection. Use of the air Recirculation mode during
Winter months is not recommended because it may cause
window fogging.
302 UNDERSTANDING YOUR INSTRUMENT PANEL