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 245 of 1015

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 4.

Connect lead 26 to horn solenoid, Connect a jumper wire to vehicle chassis ground and

the other end to lead 25 terminal on horn solenoid. Horn should sound.

a.

If horn does not sound, replace horn solenoid (para. 3-103).

b.

If horn sounds, connect lead 26 and go to test 3.

Test 3. Test horn switch.

Step 1.

Disconnect lead 25 from horn switch.

Step 2.

Connect one end of a jumper wire to vehicle chassis ground and touch opposite end to

lead 25 connector. Horn should sound.

If horn sounds, replace horn switch (para. 3-104).

END OF TESTING!

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