TM 9-2320-302-20
0010 00-5
Table 1. Electrical System Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Marker and Taillight Circuits - Continued
2. Left/Right Front Marker Light Does Not
Operate - Continued.
2. Remove lamp from socket.
Check for continuity between
contacts of lamp.
If continuity is indicated, go to
step
3.
If
continuity
is
not
indicated, replace lamp (WP
0088 00).
3. Check for continuity between
socket and ground.
If continuity is indicated, go to
step
4.
If
continuity
is
not
indicated, repair ground lead (WP
0119 00).
4. Disconnect lead 46E/46F from
lead 46. Check for +12 VDC at
lead 46.
If +12 VDC is present, repair lead
46E/46F. If voltage is not present,
repair lead 46 (WP 0119 00).
3. One or More Cab Marker Lights Does Not
Operate.
1. Inspect light bulbs.
Replace
bulbs
if
broken
or
defective (WP 0089 00).
2. Remove
lamp(s)
from
defective circuit(s). Check for
continuity between socket and
ground.
If continuity is indicated, go to
step
3.
If
continuity
is
not
indicated, replace lamp(s) (WP
0089 00).
3. Disconnect ground lead from
marker light(s). Check for
continuity
between
ground
lead(s) and ground.
If continuity is indicated, repair
lead(s) 46. If continuity is not
indicated, repair ground lead(s)
(WP 0119 00).
4. Both Taillights Do Not Operate, But All Marker
Lights Operate.
1. Inspect light bulbs.
Replace
bulbs
if
broken
or
defective (WP 0087 00).
2. Disconnect lead 23A from
taillight terminal. Check for
+12 VDC at lead 23A.
If +12 VDC is present, repair
terminal connector (WP 0119 00).
If voltage is not present, repair
lead 23A (WP 0119 00).
Blackout Light Circuits
1. None of Blackout (B/O) Lights Operate.
Check B/O 15A fuse.
Replace 15A fuse if defective (WP
0071 00).
2. None of Blackout (B/O) Stoplights Operate.
1. Inspect light bulbs.
Replace
bulbs
if
broken
or
defective (WP 0086 00).
2. Disconnect
B/O
stoplights
relay from connector. Check
for +24 VDC at connector 30.
If +24 VDC is present, go to step
3. If voltage is not present, repair
lead connector 421V (WP
0119 00).
3. Check
for
+24
VDC
at
connector 85.
If +24 VDC is present, go to step
4. If voltage is not present, repair
lead 420N (WP 0119 00).
4. Check for continuity between
connector 86 and ground.
If continuity is indicated, go to
step
5.
If
continuity
is
not
indicated, repair ground lead (WP
0119 00).
