Table 4. Electrical System Troubleshooting Procedures - Continued.

TM 9-2320-312-24-1

TROUBLESHOOTING PROCEDURES - CONTINUED

0006 00

Table 4. Electrical System Troubleshooting Procedures - Continued.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

LIGHT SYSTEMS - CONTINUED

Reset circuit breaker(s).

7. Trailer Lights Inoperative (12-Volt Trailer) -

3. Check circuit breaker panel

for any tripped circuit

Continued.

breakers.

a. If 12Vdc is present, refer

4. Use multimeter to check for

to trailer manual for

12Vdc of 7-pin trailer

troubleshooting instruc-

receptacle at pin K.

tions.

b. If 12Vdc is not present, go

to step 4.

Repair or replace damaged or

5. Use multimeter to check

wires and connectors between

corroded wires and connectors

components of 12-volt trailer

(WP 0120 00).

light circuit.

Reconnect cable.

8. Trailer Lights Inoperative (24-Volt Trailer).

1. Ensure tractor-to-trailer 24-

volt cable is properly

connected (TM 9-2320-312-

10).

a. Clean cable connections

2. Inspect 24-volt cable and

as required.

receptacles for bent or

corroded pins.

b. Repair bent or damaged

pins (WP 0120 00).

Reset circuit breaker(s).

3. Check for tripped circuit

breakers in 24-volt converter

box (WP 0099 00).

a. If 24Vdc is present, refer

4. Use multimeter to check for

to trailer manual for

24 Vdc at 12-pin trailer

troubleshooting instruc-

receptacle at pin K.

tions.

b. If 24Vdc is not present, go

to step 4.

Replace failed relay(s) (WP

5. Remove trailer relays located

in 24-volt converter box (WP

0099 00).

0099 00). Use multimeter to

test relay internal circuit.

Replace failed circuit breaker(s)

6. Use multimeter to test trailer

circuit breakers, located in

(WP 0099 00).

24-volt converter box (WP

0099 00).

0006 00-15