GMC 1982 Light Duty Truck Service Manual page 302

3B4-14 STEERING COLUMNS
C O N D IT IO N
Front or rear turn signal
lights not flashing
Stop light not on when
turn indicated
Turn indicator panel
lights not flashing
S IG N A L SW ITC H D IA G N O S IS
POSSIBLE CA USE
A. Burned out fuse
B. Burned out or
damaged turn signal
bulb
C. High resistance
connection to ground
at bulb socket
D. Loose chassis to
column connector
E.
Disconnect column to
chassis connector.
Connect new switch
into system and
operate switch
by hand.
If turn signal lights
are now on and
flash, turn signal
switch is inoperative.
F.
If vehicle lights do
not operate, check
chassis wiring harness
to light sockets for
opens, grounds, etc.
A. Burned out fuse
B. Loose column to
chassis connection
C. Disconnect column to
chassis connector.
Connect new switch
into system without
removing old. Operate
switch by hand.
If brake lights work
with switch in the
turn position, signal
switch is defective
D. If brake lights do not
work check connector
to stop light sockets
for grounds, opens,
etc.
A. P ned out bulbs
B. High resistance to
ground at bulb socket
C. Opens, grounds in
wiring harness from
front turn signal bulb
socket to indicator
lights
Fig. 3 B 4 -1 5 -T u rn Signal S w itch Diagnosis Chart C
C O R R E C T IO N
Replace fuse and
A,
check operation
Replace bulb
B.
C. Remove or repair
defective connection
and check operation
D.
Connect securely and
check operation
E.
Replace turn signal
switch.
F . Repair chassis wiring
as required using
manual as guide
A.
Replace fuse and
check operation
B. Connect securely and
check operation
C. Replace signal switch
D. Repair connector to
stop light circuits
using manual as guide.
A. Replace bulbs
B. Replace socket
C.
Locate and repair as
required. Use shop
manual as guide.