2-12. STARTING THE ENGINE (ABOVE +32°F) (O°C) (Contd)
(1) Noisy engine and/or excessive engine vibration.
(2) Oil pressure does not register, or suddenly drops to less than 15 psi (103 kPa) on M939A1 series; 10
psi (69 kPa) on M939A2 series, as indicated by engine oil pressure gauge (6).
(3) Sudden increase in coolant temperature beyond normal operating temperature, 175°-200°F (79°-
93°C), as indicated by engine coolant temperature gauge (5).
Engine continues to run after ignition switch (1) and battery switch (3) are turned to OFF positions.
After an emergency shutdown, the engine will not restart until unit maintenance resets the fuel shutoff
valve. On M939A2 series vehicles, position EMERGENCY ENGINE STOP control (7) to reset.
Turn vehicle light switch (9) to desired position (para. 2-18).
2-13. COLD WEATHER STARTING (BELOW +32°F) (O°C)
Perform steps a. through k. in paragraph 2-12.
Press ether start switch (8) during cranking. Allow three seconds for ether to discharge into system after
releasing switch (8).
Do not operate starter continuously for more than 10 seconds at a time or
with headlights on. Wait 10-15 seconds between periods of starter
If engine cranks but will not start, turn battery switch to OFF position. See
troubleshooting, malfunction 3.
Release engine ignition switch (1) after engine starts.