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 930 of 1313

LOW AIR PRESSURE WARNING BUZZER WILL NOT SHUT OFF (AIR PRESSURE GAUGES AT NORMAL

SYSTEM PRESSURE) - Continued

c.

Install wires 578 and 578A to primary low air pressure switch.

d.

Disconnect wires 57 and 578A from secondary low air pressure switch.

e.

Connect multimeter red lead to contact end of pressure switch. Refer to point to point schematics.

f.

Connect multimeter black lead to other contact end of pressure switch.

g.

Meter reading should be less than 300 ohms.

CONDITION/INDICATION

IS SECONDARY LOW AIR PRESSURE SWITCH WORKING PROPERLY?

DECISION

NO - Replace secondary low air pressure switch (Volume 2, WP

0342). Go to Step (6) to verify problem is

solved.

YES - Go to Step (3).

TM 9-2320-272-23-1

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