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 144 of 1275

TM 9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

d. STARTER MOTOR CIRCUIT (M109A4/M109A5) —

(1) ENGINE DOES NOT CRANK; ALL ELECTRICAL

CONTINUED

ACCESSORIES OPERATE — CONTINUED

CONTINUED FROM STEP F

1. Place red lead of multimeter in socket B

(lead 400-4595) and black lead to ground.

2. Turn MASTER switch ON and check for

voltage.

3. Turn MASTER switch OFF.

Is voltage present?

Repair or replace lead 14B of

driver’s bulkhead-to-master relay

wiring harness (para 8-46).

H

1. Reconnect connector to starter protection

relay.

2. Disconnect driver’s bulkhead-to-master

relay wiring harness from voltage regulator.

3. Place a jumper wire from pin A (lead 2) to

socket A (lead 2).

4. Place red lead of multimeter on pin B

(lead 400-459B) and black lead to ground.

5. Turn MASTER switch ON and check for

voltage.

6. Turn MASTER switch OFF.

Is voltage present?

Repair or replace lead 400-459B

CONTINUED ON NEXT PAGE

3-44

of driver's bulkhead-to-master

relay wiring harness (para 8-46).