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 438 of 1275

TM9-2350-311-20-1

3-3 TROUBLESHOOTING CHART — CONTINUED

ae. ELECTRIC FUEL PUMP CIRCUIT — CONTINUED ENGINE MISSES WHEN LOW ON FUEL; ONE OR BOTH

FUEL PUMPS FAIL TO OPERATE — CONTINUED

CONTINUED FROM STEP Q

R

1.

2.

3.

4.

With lead 76B still disconnected from engine

oil pressure switch, disconnect lead 76 from

left fuel pump.

Place jumper wire from lead 76B to ground.

Turn MASTER switch ON and check for

fuel flow.

Turn MASTER switch OFF.

Is there fuel flow?

I

I Go to step T.

1.

2.

3.

4.

5.

Reconnect lead 76B to engine oil pressure

switch.

With lead 76 disconnected from left fuel

pump, disconnect lead GND from fuel pump.

Using jumper wires, connect lead GND to

bulkhead and lead 76 to positive battery

terminal.

Turn MASTER switch ON and check for

fuel flow.

Turn MASTER switch OFF.

Is there fuel flow?

I

Reconnect fuel lines and replace

Reconnect fuel lines and repair or replace

lead 76 of bulkhead-to-headlights/bilge

pump wiring harness (para 8-47).

3-338

left fuel pump (para 6-5).