C6.6 Marine Generator Set Caterpillar

Probable Causes

• Power generator

• Battery cables and/or batteries

• Starting motor solenoid or starting circuit

• Starting motor and/or flywheel ring gear

• Electrical power supply

• Internal engine fault

• Control system

Recommended Repairs

Power Generator

Make sure that the power generator is free to rotate. If the power generator does not rotate, refer to the documentation that is supplied by the OEM.

Battery Cables and/or Batteries

1. Inspect the main power switch, battery posts, and battery cables for loose connections and corrosion. If the battery cables are corroded, remove the battery cables and clean the battery cables. Clean the battery posts. Replace the cables. Tighten any loose connections.

2. Inspect the batteries.

   1. Charge the batteries.

   2. Load test the batteries. Refer to Systems Operation, Testing and Adjusting, "Battery - Test".

Starting Motor Solenoid or Starting Circuit

1. Test the operation of the starting motor solenoid. Refer to Systems Operation, Testing and Adjusting, "Electric Starting System - Test".

2. Check the wiring to the starting motor solenoid.

Starting Motor and/or Flywheel Ring Gear

1. Test the operation of the starting motor. Check the wiring for the starting motor. Refer to Systems Operation, Testing and Adjusting, "Electric Starting System - Test".

2. Inspect the pinion on the starting motor and the flywheel ring gear for damage.

Electrical Power Supply

If there is no electrical power supply, investigate the cause and rectify any defects. Refer to Systems Operation, Testing and Adjusting, "Charging System - Test".

Internal Engine Fault

1. Remove the glow plugs. Refer to Disassembly and Assembly, "Glow Plugs - Remove and Install".

2. Attempt to rotate the crankshaft through 360 degrees in both direction. If the crankshaft rotates correctly but fluid is expelled from the hole for the glow plug, investigate the cause of the fluid in the cylinder.

3. If the crankshaft rotates correctly and no fluid is expelled, install the glow plugs. Refer to Disassembly and Assembly, "Glow Plugs - Remove and Install".

4. If the engine does not rotate in Step 2, disassemble the engine. Refer to Disassembly and Assembly.

5. Inspect the internal components for the following conditions:

   • Seizure

   • Broken components

   • Bent components

Control System

Check that power is being provided from the control system to the solenoid on the starting motor.

Note: If power is not reaching the solenoid on the starting motor, the engine will not crank.