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 246 of 828

TM 9–2350–311–20–2

3–134

3–3

TROUBLESHOOTING — CONTINUED

j.

NBC SYSTEM CIRCUIT — CONTINUED

(5)

NBC CONTROL BOX ASSEMBLY INDICATOR

LIGHT ILLUMINATES, BUT CANNONEER NO.

1’S M3 ELECTRICAL AIR HEATER DOES NOT

OPERATE. —

CONTINUED

Repair wire 8 (para 17–4).

C

CONTINUED FROM STEP B

Replace J2 connector on

NBC control box assembly

(para 17–4).

yes

no

END OF TASK

PIN A

–

J2 CONNECTOR

WIRE 8

1.

Reconnect wire 136B to cannoneer no. 1’s M3

electrical air heater.

2.

Place one multimeter lead in socket A and other

lead to pin A of J2 connector on NBC control box

assembly.

3.

Check for continuity.

Is continuity present?

Repair wire 136B of NBC

power lead assembly

(para 8–9).

yes

no

J2 CONNECTOR

+

SOCKET A

NBC CONTROL

BOX ASSEMBLY

C