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 256 of 1275

TM 9-2350-311-20-1

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TROUBLESHOOTING

CHART — CONTINUED

m. ALTERNATOR CIRCUIT (M109A2/M109A3) —

ALTERNATOR FAILS TO CHARGE BATTERIES; GAGE

CONTINUED

INDICATION: NOT CHARGING, UNSTEADY OR

INACCURATE READING

INITIAL SETUP

Configurations

.

References

M109A2/M109A3

TM 9-2350-311-10

TM 9-6140-200-14

T

O

oI

S

General mechanic’s tool kit (item 64,

Appx H)

.

Equipment Conditions

Multimeters (item 36, Appx H)

Engine compartment access cover removed (para 11-5)

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

Engine access door open

(TM 9-2350-311-10)

(Long test leads may be needed for some tests;

Transmission access doors open (TM 9-2350-311-1 0)

16 AWG wire may be used as an extension.)

CAUTION

I

Extremely low battery electrolyte levels will cause a low

voltage indication on BATTERY indicator on portable

instrument panel. Regulators can be damaged by

attempts to adjust rheostat beyond its stops when the

only problem is dry batteries.

NOTE

Vehicle idle speed must be 750 rpm in order for

alternator to charge properly. Check idle speed before

troubleshooting (TM 9-2350-311-10).

1. Run engine at 1000 rpm.

2. Place red lead of multimeters on battery

positive terminal and black lead to ground.

3. Check for voltage.

4. Turn engine off.

Is voltage 27.5 Vdc or higher?

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CONTINUED ON NEXT PAGE

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