TM-9-2350-311-20-2

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR CAB, ARMAMENT, SIGHTING AND FIRE CONTROL, ELEVATING AND TRAVERSING SYSTEMS AND ASSOCIATED COMPONENTS

DECEMBER 1993

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3–3

TROUBLESHOOTING — CONTINUED

j.

NBC SYSTEM CIRCUIT

The NBC system consists of an NBC control box assembly, M2A2 air purifier, and gunner’s, cannoneer no. 1’s,

section

chief’s, and assistant gunner’s M3 electric air heater.

All power to the NBC components is controlled through the NBC power switch which is accompanied by an indicator light.

WIRING DIAGRAM

SCHEMATIC DIAGRAM

NBC CONTROL BOX

J2

A

B

C

D

E

F