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 370 of 1275

TM 9-2350-311 -20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

w. STOP LIGHT CIRCUIT — CONTINUED

B.O. STOP LIGHT FAILS TO OPERATE; ALL OTHER

LIGHTS OPERATE — CONTINUED

CONTINUED FROM STEP A

B

1. Install inoperative B.O. stop light assembly

(para 8-25).

2. Disconnect lead 23 of bulkhead-to-driver’s

instrument panel wiring harness from taillight

lead assembly.

3. Place red lead of multimeters in lead 23 and

black lead to ground.

4. Turn MASTER switch ON, place main light

switch to B.O. DRIVE position, apply parking

brake, and check for voltage.

5. Turn MASTER and main light switches OFF.

Is voltage present?

Replace taillight lead assembly

(para 8-25).

C

1. Reconnect lead 23 of bulkhead-to-driver’s

instrument panel wiring harness to taillight

assembly.

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 N (lead 23).

4. Turn MASTER switch ON, place main light

switch to B.O. DRIVE position, apply parking

brake, and check B.O. stop light for

operation.

5. Turn MASTER and main light switches OFF.

Does B.O. stop light operate?

Replace light switch (para 8-17).

I

Repair or replace lead 23 of bulkhead-to-

driver’s instrument panel wiring harness

(para 8-50).

I

END OF TASK

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