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 274 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 A

I

NOTE

For steps H, 1, J, and K use heavy jumper wires with

alligator clips.

I

. . .

.

3.

4.

5.

6.

7.

8.

9.

Disconnect powerplant wiring harness from

alternator.

Place jumper wires from pin C (lead 3) of

alternator to battery negative terminal and

pin A (lead 1) of alternator to positive

terminal of same battery to apply 12 Vdc

to alternator field.

Place a jumper wire from pin E to socket E

(lead 503).

Turn MASTER switch ON and run vehicle

engine at 1000 rpm.

Set multimeter on ac scale, and place red

lead of multimeter on pin B (lead 500) and

black lead on pin D (lead 501).

Check for voltage.

Place red lead of multimeter on pin F (lead

502) and black lead on pin B (lead 500).

Check for voltage.

Turn MASTER switch and engine OFF.

Is voltage above 27.5 Vat?

Replace alternator (para 8-2).

CONTINUED ON NEXT PAGE

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