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 146 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 J

1. Reconnect connector to voltage

2.

3.

4.

5.

regulator.

Disconnect lead 14 from output side of

neutral safety switch.

Place red lead of multimeter on lead 14 and

black lead to ground.

Turn MASTER switch ON, push STARTER

switch, and check for voltage.

Turn MASTER switch OFF.

Is voltage present?

Go to step M.

1. Reconnect lead 14 to output side of neutral

safety switch.

2. Disconnect driver’s bulkhead-to-master

relay wiring harness from driver’s bulkhead.

3. Place a jumper wire from socket B to pin B

(lead 400-459B).

4. Place red lead of multimeter in socket T

(lead 14) and black lead to ground.

5. Turn MASTER switch ON, push STARTER

switch, and check for voltage.

6. Turn MASTER switch OFF.

Is voltage present?

Repair or replace lead 14 of driver’s

bulkhead-to-master relay wiring

harness (para 8-46).

Repair or replace lead 14 of bulkhead-

to-portable instrument panel wiring

harness (para 8-49).

3-46