Operation and maintenance manual

QSB4.5 and QSB6.7 Troubleshooting Symptoms Charts
Section TS - Troubleshooting Symptoms Page TS-39
Engine Will Not Crank or Cranks Slowly (Air Starter)
Cause Correction
STEP 1
Air pressure is low in the air tanks
.............
Increase air pressure with an external air source.
Refer to the OEM service manual.
OK
Go To Next Step
STEP 2
Engine-driven units are engaged
.............
Disengage engine-driven units. Refer to the OEM
Service Manual.
OK
Go To Next Step
STEP 3
Lubricating oil level above specification
.............
Check the oil level. Verify the oil pan capacity. Fill
the system to the specified level. Refer to Section
V.
OK
Go To Next Step
STEP 4
Lubricating oil does not meet specifications for
operating conditions
.............
Change the oil and filters. Refer to Section 5. Use
the oil recommended in Section V.
OK
Go To Next Step
STEP 5
Electrical system is "open" (blown fuses, broken
wires, or loose connections)
.............
Check the fuses, wires, and connections. Refer to
the OEM service manual and manufacturer's
wiring diagram.
OK
Go To Next Step
STEP 6
Battery charge is low
.............
Check battery. If the battery is low, check the
alternator for proper charging. Charge the battery,
and replace if necessary. Refer to the OEM
service manual.
OK
Go To Next Step
STEP 7
Keyswitch circuit is malfunctioning
.............
Check the vehicle, equipment, or vessel keyswitch
circuit. Refer to the OEM service manual.
OK
Go To Next Step
STEP 8
Starter solenoid is not receiving voltage
.............
Check the battery supply to the starter solenoid.
Refer to the OEM service manual.
OK
Go To Next Step
STEP 9
Starting motor is malfunctioning or starting motor is
not correct
.............
Check the starting motor operation. Compare the
starting motor with the engine and vehicle
specifications. Refer to the manufacturer's
instructions.
OK
Go To Next Step