Chevrolet 1977 light duty truck, Service Manual

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SPECIFICATIONS
CRUISE-MASTER
Solenoid R esistan ce................................................................................................................................................................. 5 ohms ± 1/4 ohm
Solenoid Wire R esista n ce......................................................................................................................................................................
40 ohms
Maximum allowable Vacuum Leakage rate for Servo u n i t .................................................................. 5 inches of Vacuum Per Minute
Not Greater than 1 inch of Vacuum per 10 seconds
Operational Test S p eed ..............................................................................................................................................................................
5 5
MPH
RADIO
GENERAL DESCRIPTION
A M and A M / F M radios only are available on light
duty trucks.
R e a r speakers are available for certain series o f C-K
and G Trucks.
C-K model trucks incorporate a w indshield antenna.
The a n te n n a lead snaps onto the center o f the
windshield, inside the vehicle. G model an ten n as are
m ounted externally on the right front fender.
D IA G N O S IS
T h e ra d io trouble diagnosis guide is intended as an
aid in locating m in o r faults which can be corrected
w ithout a specialized knowledge o f radio and without
special radio test equipm ent. If the suggestions given
here do not affect a correction, fu rth er testing should be
done only by a trained radio technician having pro p er
test equ ip m en t.
R A D IO DEAD
T u rn on radio.
N o Thum p Heard
Check fuse.
Fuse blown-Check receiver and speaker connectors.
Connectors loose or defective-Correct as required.
Connectors okay-Check
speaker by substituting a
known good speaker.
Radio does not play even with a known good
substitute speaker-Defective receiver. Remove for
servicing.
Radio plays with substitute speaker- Replace
speaker.
Thum p H eard
Check a n te n n a connection at back o f radio and at
base o f w indshield or antenna.
Connections defective-Substitute a known good
lead-in cable.
Radio plays-Defective cable.
Radio still won't play, even with a known good
lead-in cable-Substitute and trim a known good
radio.
Good radio plays-Defective radio.
Good radio still won’t play-Defective antenna.
C hange windshield or antenna.
R A D IO C U TS ON AND OFF
Check for defective or loose receiver o r an ten n a
connectors at rear o f radio or base o f windshield or
antenna.
Defective or loose connectors-Repair as necessary.
Connectors okay-Substitute a known good lead-in
cable.
Radio plays okay-Defective cable.
Radio still cuts out with a known good lead-in
cable-Check speaker by substituting a known good
speaker.
Radio plays okay-Replace speaker.
Radio still plays intermittently, even with a known
good speaker-Defective receiver.
R A D IO S T A T IO N S M IX TO G ETH ER
T rim radio as described earlier in this section.
However, if two or more signals are picked up at the
same time, there is no known way to separate them.
R A D IO N O ISY
Static-Start engine, rev up engine several times, and
listen for speaker static.