TM-9-2320-272-23-1

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

TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5

SEPTEMBER 2012

TM-9-2320-272-23-1 - Page 916 of 1313

FIELD MAINTENANCE

HORN INOPERATIVE

INITIAL SETUP:

Tools and Special Tools

Tool Kit, General Mechanic's: Automotive

(Volume 5, WP

0826, Table 1, Item 56)

Multimeter

(Volume 5, WP

0826, Table 1, Item 34)

Test Set, Electronic Systems

(Volume 5, WP

0826, Table 1, Item 51)

Personnel Required

(2)

References

Point to Point Schematics

References (cont.)

Volume 2, WP

0307

Volume 2, WP

0343

Volume 2, WP

0344

Volume 3, WP

0352

Volume 5, WP

0805

Equipment Condition

Vehicle parked and engine shut down.

(TM

9-2320-272-10)

TROUBLESHOOTING PROCEDURE

HORN INOPERATIVE

NOTE

Conduct these malfunction tests if horn is inoperative. This procedure will check for correct

air and voltage supply, faulty wiring, horn solenoid and switch.

TM 9-2320-272-23-1

0109

0109-1