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 199 of 1015

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Test 4. Test voltage input to protective control box.

Step 1.

Set multimeter to 50-volt range.

Step 2.

Disconnect harness connector at protective control box.

Step 3.

Place battery switch to ON.

Step 4.

Connect multimeter positive lead to pin A (lead 459) at harness connector and negative

lead to ground.

a.

Multimeter should indicate voltage. If voltage is not indicated, repair broken lead

459 (para. 3-131).

b. If voltage is indicated, go to step 5.

Step 5.

Place battery switch to OFF position.

Step 6.

Connect multimeter positive lead to pin C (lead 81) at harness connector and negative

lead to ground.

a.

Multimeter should indicate voltage. If voltage is not indicated, repair broken lead 81

(para. 3-131).

b.

If voltage is indicated, go to test 5.

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