Jeep Grand Cherokee Owner's Manual page 402

400 UNDERSTANDING YOUR INSTRUMENT PANEL
Summer Operation
NOTE: In some cases during high temperature trailer
tow operation the Air Conditioning system performance
may be reduced. This is to help protect the engine from
overheating during the high load condition.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other
obstructions.
Vacation Storage
Anytime you store your vehicle, or keep it out of service
(i.e. vacation) for two weeks or more, run the air condi-
tioning system at idle for about five minutes in the fresh
air and high blower setting. This will ensure adequate
system lubrication to minimize the possibility of com-
pressor damage when the system is started again.