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 236 of 1015

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Test 3. Test instrument cluster voltage feed.

Step 1.

Place battery switch to OFF position.

Step 2.

Remove instrument cluster panel (para. 3-83).

Step 3.

Disconnect lead 27 from each gauge.

Step 4.

Place battery switch to ON position.

Step 5.

Set multimeter to 50-volt range.

Step 6.

Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 27.

Multimeter should indicate battery voltage.

If battery voltage is not indicated, disconnect instrument cluster wiring harness lead 27

from power source lead 27 and go to step 7.

Step 7.

With multimeter negative lead connected to ground, touch positive lead to circuit 27

connector at instrument cluster, Multimeter should indicate battery voltage.

a.

If battery voltage is indicated, replace instrument cluster wiring harness

(para. 3-130).

b.

If battery voltage is not indicated, and voltage was correct in test 1, step 9, repair

power source lead 27 (para. 3-131).

END OF TESTING!

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