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 350 of 1275

TM 9-2350-311 -20-1

3-3 TROUBLESHOOTING CHART —

CONTINUED

u.

SERVICE HEADLIGHTS, TAILLIGHT, AND STOP (3) RIGHT OR LEFT HEADLIGHT FAILS TO OPERATE;

LIGHT CIRCUIT — CONTINUED

ALL OTHER LIGHTS OPERATE

Personnel Required

General mechanic’s tool kit (item 64, App

X

H)

Two

Multimeters (item 36, App

X

H)

TA-1 probe kit (item 43, App

X

H)

,

Equipment

Conditions

(Long test leads may be needed for some tests;

Engine access door open (TM 9-2350-311-10)

16 AWG wire may be used as an extension.)

Transmission access doors open (TM 9-2350-311-10)

NOTE

Both headlight assemblies have identical wiring. The

following procedures apply to both left and right

headlight assemblies.

A

1. Disconnect bulkhead-to-driver’s instrument

panel wiring harness from dimmer switch.

2. Place a jumper wire from socket G (lead 16)

to socket E (lead 18).

3. Turn MASTER switch ON and place main

light switch in SER. DRIVE position.

4. Check headlight for operation.

5. Turn MASTER switch OFF.

Does headlight operate?

Replace dimmer switch (para 8-17).

CONTINUED ON NEXT PAGE

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