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 362 of 1275

TM 9-2350-311 -20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

v. B.O. MARKERS AND B.O. DRIVE LIGHTS

(2) REAR B.O. MARKER LIGHTS FAIL TO OPERATE;

CIRCUIT — CONTINUED

ALL OTHER LIGHTS OPERATE — CONTINUED

CONTINUED FROM STEP B

C

1. Install B.O. marker assembly (para 8-25)

2. Disconnect lead 24 of bulkhead-to-driver’s

instrument panel wiring harness from taillight

lead assembly.

3. Place red lead of multimeters in lead 24 and

black lead to ground.

4. Turn MASTER switch ON, place main light

switch to B.O. MARKER position, and check

for voltage.

5. Turn MASTER and main light switches OFF.

Is voltage present?

Replace taillight lead assembly

Repair or replace lead 20/24 of

bulkhead-to-driver’s instrument panel

wiring harness (para 8-50).

END OF TASK

(para 8-25).

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