TM
9-2320-363-20-1
Table 3-1.
Troubleshooting
(Cont)
Malfunction
Test or Inspection
Corrective Action
ELECTRICAL
SYSTEM (CONT)
Turn Signal and Stoplight
Circuits (Cont)
1.
NEITHER STOPLIGHT OPERATES.
Step
1.
Step 2.
Step
3.
Step 4.
Step
5.
Step
6.
Check
stoplight
20A
fuse.
.
If defective,
replace
20A fuse (page 4-204).
Inspect
light bulbs.
.
Replace
if broken or defective
(page 4-284).
Disconnect
leads 420A
and 420K
from stoplight switch. Check for continuity
between
switch contacts
while
pressing
switch.
.
If continuity
is indicated,
go to step 4. If no continuity is
indicated,
replace
stoplight switch (page
4-228).
Disconnect
leads 420A
and 420K
from vehicular
light switch. Check for
continuity between
leads
420A
and 420K
with stoplight switch closed.
-
If continuity
is
indicated,
go
to
step
5.
If
no
continuity
is
indicated,
repair
lead
420A
or
lead
420K
(page
3-2).
Disconnect
lead
420C
from
vehicular
light
switch.
Disconnect
lead
36C
from
turn signal switch.
Check
for
continuity
between
lead 420C
and 36C.
.
If continuity
is indicated,
go to step 6. If no continuity is
indicated,
repair
lead 420C
or lead 36C
(page 3-2).
Disconnect
lead 36C
from vehicular
turn signal switch. Check for +12 VDC
in lead 36C with stoplight switch closed.
.
If +12 VDC
is present,
replace
turn
signal
switch
(page
4-168).
If
no
voltage
is present,
replace
vehicular
light
switch
(page
4-170).
2.
LEFT
STOPLIGHT
NOT
OPERATING.
Step
1.
Inspect
light
bulb.
.
Replace
if
broken
or
defective
(page
4-284).
Step
2.
Remove
lamp
from
left
stoplight
(page
4-284).
Check
for continuity between
contact points.
.
If continuity
is indicated,
go to step 3. If no continuity
is
indicated,
replace
lamp
(page
4-284).
Step
3.
Remove
left
stoplight
lamp.
Check
for
continuity
between
socket
and
ground.
.
If continuity
is
indicated,
go
to
step
4.
If no
continuity
is
indicated,
repair
ground
lead
(page
3-2).
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