TM-9-2320-272-24-1

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 1 OF 4

JUNE 1998

TM-9-2320-272-24-1 - Page 225 of 1015

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 6.

Multimeter should read continuity. If continuity is not read, check wiring harness for

broken, frayed, or pinched wires.

a. Repair broken, frayed, or pinched wires (para. 3-131).

b.

If system is still not operational, go to test 4.

Test 4. Test wiring harness for short,

Step 1.

Remove jumper wire from light wire to ground that was connected in test 3, step 3.

Step 2.

With multimeter set for continuity, and wires disconnected as in step 1, connect

multimeter negative to vehicle chassis ground. Touch positive lead to wire corresponding

to defective lead.

Step 3.

Multimeter should not read continuity (infinite reading). If there is a reading, the wiring

harness has a shorted lead.

Step 4.

Check harness for short lead by visually locating frayed or pinched wires.

a. Repair frayed or pinched wires (para. 3-131).

b.

If system is still not operational, perform malfunction 24.

END OF TESTING!

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