Ram Trucks 2013 Chassis Cab - Owner Manual - Manual (Page 261)

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 Defrost mode to improve window
clearing operation. Recirculation will be disabled auto-
matically 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 “Maintaining Your
Vehicle” 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 “Maintaining Your Vehicle” for proper
coolant selection. Use of the air Recirculation mode
during Winter months is not recommended because it
may cause window fogging.
Vacation/Storage
Any time 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
fresh air with the blower setting in high. This will ensure
adequate system lubrication to minimize the possibility
of compressor damage when the system is started again.
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UNDERSTANDING YOUR INSTRUMENT PANEL 259