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 197 of 1015

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).

MALFUNCTlON

TEST OR INSPECTION

CORRECTIVE ACTION

8. STARTER MOTOR INOPERATIVE; NO SOLENOID THUMP

Test 1. Test battery and starter systems (malfunctions 2, 3, 4, 6, and 7).

Test 2. Test starter lockout reset.

Step 1.

Disconnect harness connector from protective control box.

Step 2.

Connect harness connector to protective control box to reset starter lockout switch.

Step 3.

Start engine (TM 9-2320-272-10).

a.

If engine fails to start, go to test 3.

b.

If engine starts, replace alternator (para. 3-79 or 3-80).

Test 3. Test battery switch for voltage.

Step 1.

Set multimeter to 50-volt range.

Step 2.

Disconnect lead 81A (pin A) from battery switch.

Step 3.

Connect multimeter positive lead to contact end of lead 81A and negative lead to ground.

a.

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

lead 81A/81 (para. 3-131).

b. If voltage is indicated, go to step 4.

2-109