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 276 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

n. ALTERNATOR CIRCUIT (M109A4/M109A5) —

ALTERNATOR FAILS TO CHARGE BATTERIES; GAGE

CONTINUED

INDICATION: NOT CHARGING, UNSTEADY OR

INACCURATE READING — CONTINUED

CONTINUED FROM STEP I

J

1. Reconnect powerplant wiring harness to

rectifier.

.

2. Disconnect rectifier-to-voltage regulator

wiring harness from rectifier.

3. Place jumper wires from pin E (lead 3) to a

battery negative terminal and pin B (lead 1 ) to

positive terminal of same battery

to apply 12 Vdc to alternator field.

4. Turn MASTER switch ON and run vehicle

engine at 1000 rpm.

5. Set multimeter on dc scale and place red lead

of multimeter on pin C (lead 2A) and black

lead to ground.

6. Check for voltage.

7. Turn MASTER switch and engine OFF.

Is voltage above 27.5 Vdc?

Replace rectifier (para 8-5)

‘CONTINUED ON NEXT PAGE

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