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 366 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART —

CONTINUED

v.

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

(4) ALL B.O. MARKER LIGHTS FAIL TO OPERATE; ALL

CIRCUIT —

CONTINUED

OTHER LIGHTS OPERATE

Tools

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

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

Multimeters (item 36, Appx H)

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

1.

Disconnect bulkhead-to-driver’s instrument

2.

3.

4.

panel wiring harness from main light switch.

Place a jumper wire from socket F (lead

15) to socket E (lead 20/24).

Turn MASTER switch ON, apply brake pedal,

and check B.O. marker lights for operation.

Turn MASTER switch OFF.

I

Do B.O. marker lights operate?

Replace light switch (para 8-17)

I

Repair or replace lead 19 and/or 20/24

of bulkhead-to-driver’s instrument panel

I

wiring harness (para 8-50).

END OF TASK

3-266