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 248 of 828

TM 9–2350–311–20–2

3–136

3–3

TROUBLESHOOTING — CONTINUED

j.

NBC SYSTEM CIRCUIT — CONTINUED

(6)

NBC CONTROL BOX ASSEMBLY INDICATOR

LIGHT ILLUMINATES, BUT SECTION CHIEF’S

M3 ELECTRICAL AIR

HEATER DOES NOT

OPERATE. —

CONTINUED

Repair wire 12 (para

17–4).

yes

no

C

CONTINUED FROM STEP B

END OF TASK

Replace J2 connector on

NBC control box assem-

bly (para 17–4).

+

–

PIN F

J2 CONNECTOR

WIRE 12

yes

no

Repair NBC power lead

assembly (para 8–9).

1.

Reconnect lead 136D to section chief’s M3

electrical heater.

2.

Place one multimeter lead in socket F and other

lead to pin F of J2 connector on NBC control box

assembly.

3.

Check for continuity.

Is continuity present?

J2 CONNECTOR

SOCKET F

NBC CONTROL

BOX ASSEMBLY

C