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 266 of 1275

TM 9-2350-311 -20-1

3-3

TROUBLESHOOTING CHART — CONTINUED

m. ALTERNATOR CIRCUIT (M109A2/M109A3) —

ALTERNATOR FAILS TO CHARGE BATTERIES; GAGE

CONTINUED

INDICATION: NOT CHARGING, UNSTEADY OR

INACCURATE READING — CONTINUED

CONTINUED FROM STEP M

1

CAUTION

Rheostat turns easily. Do not force beyond the stops or

damage to regulator may occur.

M

7. With engine running at 1000 rpm, use a

screwdriver to adjust rheostat to obtain a

voltage reading of 27.5 to 28.5 Vdc. Turn

screwdriver counterclockwise to reduce

voltage. Slowly turn screwdriver to bring

regulated voltage up to 27.5 to 28.5 Vdc.

8. Replace pipe plug in end of voltage

regulator.

9. Turn off vehicle headlights.

10. Repeat step 4. If this check is satisfactory,

shut off engine and remove multimeters.

11. If voltage regulator cannot be adjusted,

replace regulator (para 8-3).

12. If electrical (battery) problems continue after

regulator has been properly checked

and/or adjusted, check service,

maintenance, and usage of battery

(TM 9-6140-200-1 4).

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