TM-9-2350-311-20-1

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

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR HULL, POWERPLANT, DRIVE CONTROLS, TRACKS, SUSPENSION, AND ASSOCIATED COMPONENTS

AUGUST 1994

TM-9-2350-311-20-1 - Page 444 of 1275

TM9-2350-311 -20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

af. VENTILATED FACE PIECE SYSTEM CIRCUIT

—

(1) NBC INDICATOR LIGHT FAILS TO OPERATE; NBC

CONTINUED

HEATERS AND PURIFIER OPERATE

I INITIAL SETUP I

Tools

General mechanic’s tool kit (item 64, Appx H)

Multimeter (item 36, Appx H)

TA-1 probe kit (item 43, Appx H)

A

1. Remove LED from NBC indicator light

assembly.

2. Place red lead of multimeter in center socket

and black lead to ground.

3. Turn MASTER and NBC switches ON and

check for voltage.

4. Turn MASTER and NBC switches OFF.

Is voltage present?

I

Replace LED (para 8-17).

CONTINUED ON NEXT PAGE

3-344