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 210 of 828

TM 9–2350–311–20–2

3–98

Change 2

3–3

TROUBLESHOOTING

— CONTINUED

h.

CAB LIGHTING SYSTEM

— CONTINUED

(5)

ALL CAB LIGHTS ARE OUT.

— CONTINUED

Repair or replace wire from

circuit breaker output termi-

nal B to pin F (para 8–12).

1.

Reconnect wire 138/147 to quick-disconnect at

gunner’s selector switch box assembly.

2.

Open gunner’s selector switch box assembly.

3.

Place one multimeter lead on output side of pin F

of J2 connector and other lead on input side of

pin F of J2 connector.

4.

Check for continuity.

Is continuity present?

yes

no

C

yes

no

D

CONTINUED FROM STEP C

Replace J2 connector

(para 8–12).

+

GUNNER’S

SELECTOR

SWITCH BOX

ASSEMBLY

CIRCUIT

BREAKER

1.

Place one multimeter lead on output side of pin

F of J2 connector and other lead to output

terminal B of circuit breaker.

2.

Check for continuity.

Is continuity present?

OUTPUT TERMINAL

See troubleshooting chart

para 3–3g. (1) .

END OF TASK

ALL INFORMATION ON PAGES 3–99 AND 3–100 HAS BEEN DELETED.

J2 CONNECTOR

INPUT PIN F

J2 CONNECTOR

OUTPUT PIN F

+

–

J2 CONNECTOR

PIN F

–