GMC 2002 Safari Owner's Manual page 154

Rear Heating System (Option)
You may have the optional rear heater. The three
fan thumbwheel is to the right of the radio. Turn the
thumbwheel toward HIGH for higher airflow in the
rear area. Turn the thumbwheel to OFF to turn the
system off.
Rear Air Conditioning System (Option)
-
speed You may have rear air conditioning. The rear air
conditioning thumbwheel is located to the right of the
heater controls. Turn the thumbwheel toward HIGH for
higher airflow in the rear area. Turn the switch to OFF
to turn the system off.
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