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

TM-9-2350-311-20-2 - Page 244 of 828

TM 9–2350–311–20–2

3–132

3–3

TROUBLESHOOTING — CONTINUED

j.

NBC SYSTEM CIRCUIT — CONTINUED

(4)

NBC CONTROL BOX ASSEMBLY INDICATOR

LIGHT ILLUMINATES, BUT GUNNER’S M3

ELECTRICAL AIR HEATER DOES NOT OPER-

ATE. —

CONTINUED

1.

Reconnect wire 136A to gunner’s M3 electrical

air heater.

2.

Place one multimeter lead in socket E and

other lead to pin E of J2 connector on NBC

control box assembly.

3.

Check for continuity.

Is continuity present?

Repair wire 11 (para

17–4).

C

yes

no

CONTINUED FROM STEP B

Replace J2 connector on

NBC control box assembly

(para 17–4).

END OF TASK

+

–

WIRE 11

J2 CONNECTOR PIN E

J2 CONNECTOR

SOCKET E

yes

no

Repair wire 136A of

NBC power lead assem-

bly (para 8–9).