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9-26
1977 PONTIAC SERVICE MANUAL
frequency is displayed for approximately a three to five
second interval when the radio is activated through either the
ignition or radio switches, when the station frequency is
manually or pushbutton selected, or when the volume control
knob is depressed.
The elapsed time indicator allows you to record and
store up to 19 hours and 59 minutes of travel time while the
car is in operation. New timing intervals are begun when the
button marked "reset" is depressed. This clears all stored
time and simultaneously restarts timing for the next interval.
Display of the elapsed time can be obtained whenever desired
by pushing the "E time" button. Stored time will be displayed
.
in hours and minutes separated by a steady lit colon. The
timer records only when the ignition switch is in the
ACCESSORY or ON positions. Accumulated time is
retained when the ignition is in the OFF position.
Depressing the button marked "Date" will display the
month and day of the year separated by a steadily lit colon.
The system is programmed for the correct number of days
per calendar month and with the exception of February 29,
in leap year, will automatically operate as a perpetual
calendar. The display will appear only when the ignition
switch is in either the ON or ACCESSORY positions.
Two recessed setup buttons are provided to be used for
setting the correct time or date; one at the right and one at
the left end of the digital display panel marked "HOUR" and
"MIN" respectively. A small non-breakable blunt object may
be used during the setup procedure (see Fig. 9-30). Do not
use
a
lead pencil or other object that might break and jam
the setup buttons. The buttons should be depressed and held
until the proper digit appears.
Radio stations frequently provide the exact time of the
day by referencing: "At the sound of the tone the exact time
is
...".
You can set your digital radio to the minute by
simultaneously depressing the hour and minute buttons when
the tone is heard and then setting the display to correspond
to the time provided.
CB RADIO
Two types of Civilian Band radios are available in 1977
Pontiacs (see Fig. 9-23). The first is a two-piece combination
in-dash AM/FM Stereo radio and 23 or 40 channel CB
transceiver with a common audio system and a common
display and control panel. The CB radio chassis is located in
a remote box, mounted inside the instrument panel,
connected by a cable to the main radio chassis. A common
audio speaker system is used for both the entertainment radio
and the CB unit. The displays and controls for the
combination unit are all mounted on the radio escutcheon
(see Fig. 9-3 1).
The outer left knob operates the on-off switch and
volume control for both the CB and entertainment radio. The
right knob, pushbuttons, and slide bar pertain to the
entertainment unit as usual.
The squelch circuit permits quiet standby operation
while awaiting a call from another station. Adjust the control
on a quiet channel by turning it slowly clockwise until the
background noise disappears. The receiver will resume
operation automatically when a station comes on the air. If
the control is turned further clockwise, weaker stations will
be squelched and only strong stations will be heard.
The lever in the upper right corner is the mode switch.
This places the unit in either the radio, override, or CB
position. When the unit is placed in the override position, the
entertainment radio can be interrupted by a CB signal of a
predetermined strength, set by the squelch adjustment. When
the CB message is completed, the unit
w i H
automatically turn
back to the entertainment radio. If the squelch is turned too
far counterclockwise, nothing will be received from the
entertainment radio.
The CB channel selector is located to the left of the dial
face. This switch controls both the transmitter and receiver
frequency, and may be set to any of the 23 or 40 authorized
CB channels. The channel that has been selected will be
shown on the LED channel read-out which is placed in the
upper left comer when radio is in CB or override mode.
The transceiver is designed to operate with any standard
CB antenna. The transmitter should not be operated unless
the antenna is connected. Do not connect the CB radio with
the regular car entertainment radio antenna, as it may cause
damage to the CB radio.
C A UTI
0
N : There is no internal over- voltage
protection for the CB unit. It should be switched
o f f when jump starting the car to avoid damage to
any of the electronic circuits.
A second type CB radio is the bracket mounted unit,
which is mounted below the dash or on the transmission
hump
(see
Fig. 9-32). It is available on A, B, F, X and G
models except station wagons. It has its own integral speaker
and separate controls. It can be operated with the ignition on,
and is independent of the other car radios. The squelch
control operates as above.
I
CB ANTENNA
The antenna used with all CB radios is trunk lid
mounted. The cable is routed alongside the rear speaker
wiring, and plugs into the back of the bracket mounted unit,
or into the right side of the remote box of the integral unit.
The CB radio should never be operated unless the antenna
is connected.
Whenever a CB radio is removed for any reason, and
particularly when a CB antenna is removed, the standing
wave ratio should be checked (see Fig. 9-33). This is
important, as too high a ratio will impair performance, and
if extremely high, may damage the radio
DIAGNOSIS
ALL RADIOS
Because radio problems are most often repaired at
authorized warranty repair stations, the tendency is to
remove the set when a problem is reported, without any
preliminary diagnosis. This results in a large number of radios
showing up as "NO TROUBLE FOUND" units when
received by the warranty repair stations. Many times when
this is the case, the trouble usually could have been corrected
without removal of the radio.
The inconvenience of driving without a radio while the
set is being serviced at a warranty repair station can
frequently be avoided if the following quick checks are used
to eliminate external radio system problems before removing
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