GMC 1997 Safari Owner's Manual page 164

Rear Seat Audio (If Equipped)
This feature allows rear seat passengers to listen to a
different music source than the front seat passengers
including AM-FM automatic tone control and cassette
tapes. For example, rear seat passengers may listen to a
cassette tape through headphones while the driver listens
to the radio through the front speakers. The rear seat
passengers have control of the volume for each
headphone. Be aware that the front seat audio controls
always override the rear seat audio controls.
Note that this feature is intended for rear seat
passengers. Please do not use headphones while driving.
PWR: Press this button to turn the rear seat audio
system on or off. The rear speakers will be muted when
the power is turned on. You may operate the rear seat
audio functions even when the primary radio power
is off.
VOL: Press this knob lightly so it extends.
Turn the knob clockwise to increase volume and
counterclockwise to decrease volume. Push the knob
back in to its stored position when you're not using it.
The upper VOL knob controls the upper headphone and
the lower VOL knob controls the lower headphone.
AM-FM:
Press this button to switch between AM, FMl
and FM2. If the front passengers are already listening to
AM-FM, the rear seat audio controller will not switch
between the bands and cannot change the frequency.
SEEK: Press the up arrow to tune to the next higher
station and stay there. Press the down arrow to tune to
the next lower station and stay there. The sound will
mute while seeking. The SEEK button is inactive if the
AM-FM mode on the front radio is in use.
While listening to a cassette tape, press the up arrow to
hear the next selection on the tape. Press the down arrow
to go back to the previous selection.
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