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 352 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART —

CONTINUED

u. SERVICE HEADLIGHTS, TAILLIGHT, AND STOP (4) TAILLIGHT FAILS TO OPERATE; ALL OTHER

LIGHT CIRCUIT — CONTINUED

LIGHTS OPERATE

Tools

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

Driver’s instrument panel released (para 8-17)

Multimeter (item 36, Appx H)

Taillight cover removed (para 8-25)

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

1. Remove taillight bulb (para 8-25).

2. Place red lead of multimeters in center contact

and black lead to ground.

3. Turn MASTER switch ON, place main

light switch to SER. DRIVE position, and

check for voltage.

4. Turn MASTER switch OFF.

Is voltage present?

Replace taillight bulb (para 8-25).

B

1. Install taillight bulb in socket (para 8-25).

2. Disconnect bulkhead-to-driver’s instrument

panel wiring harness from main light switch.

3. Place a jumper wire from socket F (lead 15)

to socket H (lead 21).

4. Turn MASTER switch ON and check taillight

for operation.

5. Turn MASTER switch OFF.

Does taillight operate?

Replace light switch (para 8-17).

I

Repair or replace lead 21 of bulkhead-to-

driver’s instrument panel wiring harness

(para 8-50).

END OF TASK

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