Table 1. Engine Fan Circuit Troubleshooting Procedures.

TM 9-2320-303-24-1

Table 1. Headlight Circuits Troubleshooting Procedures.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Neither Headlight Operates When Switch Is 1. Check left and right headlight

Turned On.

15A fuses.

2. Disconnect lead 420M from If +12 VDC is present at vehicular

vehicular light switch. Check light switch, go to step 3. If no

for +12 VDC at pin M.

voltage is present at vehicular

light switch, replace vehicular

light switch (WP 0065 00).

3. Disconnect left headlight

If +12 VDC is present, replace left

power relay from connector.

and right headlight power relay

Check for +12 VDC at

(WP 0072 00). If no voltage is

connector 85.

present at connector 85, repair

lead 420M.

Left Headlight Fails To Operate When Switch 1. Inspect headlight bulb.

Is Turned On.

2. Check left headlight 15A fuse.

3. Disconnect lead 14 from left If +12 VDC is present, go to step

headlight 15A fuse. Check for 4. If no voltage is present, repair

+12 VDC at lead 14.

lead.

4. Disconnect ground lead from If +12 VDC is present, repair

left headlight. Check for +12 ground lead. If no voltage is

VDC at ground lead to left present, go to step 5.

headlight.

5. Disconnect left headlight If continuity is indicated, go to

power relay from connector. step 6. If no continuity is

Check for continuity between indicated, repair ground lead.

connector 86 and ground.

6. Disconnect left headlight If +12 VDC is present, go to step

power relay from connector. 7. If no voltage is present, repair

Check for +12 VDC at lead 20.

connector 30.

7. Disconnect left low/high beam If +12 VDC is present, replace left

relay from connector. Check low/high beam relay (WP 0072

for +12 VDC at connector 30. 00). If no voltage is present, go to

step 8.

8. Check for continuity between

If continuity is present, replace

connector 87 from left

left headlight power relay (WP

headlight power relay and

0072 00). If no continuity is

connector 30 from left low/

indicated, repair lead 20L.

high beam relay.

0010 00-8