TM 9-2320-302-20
0010 00-11
Table 1. Electrical System Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Backup Light Circuits
1. Backup Lights Do Not Operate.
1. Check backup light 15A fuse.
Replace 15A fuse if defective (WP
0071 00).
2. Inspect light bulbs.
Replace
bulbs
if
broken
or
defective (WP 0087 00).
3. Disconnect lead 420JD from
backup light 15A fuse. Check
for +12 VDC at lead 420JD.
If +12 VDC is present, go to step
4. If voltage is not present, repair
lead 420JD (WP 0119 00).
4. Disconnect lead 120 from
backup light switch. Check for
+12 VDC at lead 120.
If +12 VDC is present, go to step
5. If voltage is not present, repair
lead 120 (WP 0119 00).
5. Disconnect lead 120B from
backup light switch. Press
backup light switch. Check for
continuity
between
switch
contacts.
If continuity is indicated, go to
step
6.
If
continuity
is
not
indicated, replace backup light
switch (WP 0120 00).
6. Disconnect lead 120B from
chassis harness. Check for +12
VDC at lead 120B.
If +12 VDC is present, go to step
7. If voltage is not present, repair
lead 120B between chassis and
backup light switch (WP 0119 00).
7. Check for +12 VDC at backup
receptacle
socket
120B
connector.
If +12 VDC is present, repair
receptacle socket ground leads to
ground. If voltage is not present,
repair lead 120B to chassis wiring
harness (WP 0119 00).
2. Right/Left Backup Light Does Not Operate.
1. Check backup light lamp.
Replace lamp if defective (WP
0087 00).
2. Check for continuity between
socket and ground.
If continuity is indicated, replace
backup light (WP 0087 00). If
continuity is not indicated, repair
ground lead (WP 0119 00).
3. Disconnect lead from backup
light. Check for +12 VDC at
lead.
If voltage is not present, repair red
lead (WP 0119 00).
Utility Light Circuits
1. Utility Lights Do Not Operate.
1. Inspect light bulbs.
Replace
bulbs
if
broken
or
defective (WP 0090 00).
2. Disconnect leads 420JD and
73 from 15A fuse. Check for
continuity between contacts of
15A fuse.
If continuity is indicated, go to
step
3.
If
continuity
is
not
indicated, replace 15A fuse (WP
0071 00).
