Oldsmobile 2000 Silhouette Owner's Manual page 213

To send conditioned air to the rear of the vehicle, press
the A/C button (the light will glow) on the main climate
controls. If you do not select A/C, air directed to the rear
of the vehicle will be cabin temperature.
Rear Fan Control
This option comes with the rear climate controls.
Keep the area around the base of the center instrument
panel console and the area between and under the front
seats free of objects that would obstruct airflow to the
rear of the vehicle.
3-6
The rear fan control
is located below the
climate control system,
in the switchbank.
Turn the fan to the desired setting for the amount of air
to be directed to the rear of the vehicle. The temperature
of the air will be the same as the air in the front of the
vehicle. The rear fan control in the instrument panel
switchbank has an "R" setting which allows the rear
passengers to use the rear climate control knobs to
adjust the air through the rear air outlets.
Rear Comfort Controls
The rear climate control knobs are in the panel located
above the driver's seat.