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 348 of 1275

TM 9-2350-311 -20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

u. SERVICE HEADLIGHTS, TAILLIGHT, AND STOP (2) HEADLIGHTS OPERATE ON ONE BEAM ONLY

LIGHT CIRCUIT — CONTINUED

Tools

Personel

Required

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

Two

Multimeters (item 36, Appx H)

TA-1 probe kit (item 43, App

X

H)

Equipment Condition

(Long test leads may be needed for some tests;

Engine access door open (TM 9-2350-311-1 O)

16 AWG wire may be used as an extension.)

Transmission access doors open (TM 9-2350-311-1 O)

NOTE

Both headlight assemblies have identical wiring. The

following procedures apply to both right and left

headlight assemblies.

1

A

1. Remove inoperative headlight assembly

(para 8-21 ).

2. If low beam is inoperative, place red lead of

multimeters in socket A (lead 18) and black

lead to ground.

3. Turn MASTER switch ON, place dimmer

switch in the low beam position, and check for

voltage.

4. If high beam is inoperative, place red lead of

multimeters in socket B (lead 17) and black

lead to ground.

5. Turn MASTER switch ON, place dimmer

switch in the high beam position, and check

for voltage.

6. Turn MASTER switch OFF.

Is voltage present?

Replace sealed beam unit (para

8-22).

1

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