SUPPORT AS 1066374 - Caterpillar

Probable Causes
Batteries and Battery Cables
Switches and/or Circuit Breakers (if applicable)
Starting Motor Solenoid and Starting Circuit
Starter Pinion and Flywheel Ring Gear
Engine Accessories and the Transmission (if applicable)
Hydraulic Cylinder LockRecommended Actions
Use this procedure to troubleshoot an engine that will not crank.
Table 1
Troubleshooting Test Steps    Values    Results    
1. Inspection of the Batteries and Battery Cables
A. Inspect the main power switch, battery posts, and battery cables for loose connections and for corrosion. If the battery cables are corroded, remove the battery cables and clean the battery cables. Tighten any loose connections.
B. Inspect the batteries.
C. Charge the batteries. Refer to Special Instruction, SEHS7633, "Battery Test Procedure".
Test the batteries. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6 v, 8 v, and 12 v Lead Acid Batteries".
   
Batteries
   
Result: The batteries and cables are OK.
Proceed to Test Step 2.
Result: The batteries and cables are not OK.
Repair: Make the necessary repairs. STOP.
   
2. Switches and/or Circuit Breakers (if applicable)
A. If equipped, check any switches and/or circuit breakers that may interfere with the engine cranking. Refer to the applications electrical schematic for additional information.
   
Switches and/or Circuit Breakers
   
Result: The switches and/or circuit breakers are OK.
Proceed to Test Step 3.
Result: The switches and/or circuit breakers are not OK.
Repair: Make the necessary repairs. STOP.
   
3. Starting Motor Solenoid and Starting Circuit
Test the operation of the starting motor circuit. Refer to Systems Operation/Testing and Adjusting, "Electrical System" for additional information.
   
Starting Motor Solenoid and Circuit
   
Result: The starting motor solenoid and circuit are OK.
Proceed to Test Step 4.
Result: The starting motor solenoid and circuit are not OK.
Repair: Make the necessary repairs. STOP.
   
4. Inspect the Starter Pinion and Flywheel Ring Gear
A. Test the operation of the starting motor.
B. Check the pinion clearance. Inspect the pinion and the flywheel ring gear for damage. Refer to Systems Operation/Testing and Adjusting, "Electrical System" for additional information.
   
Starter Pinion and Flywheel Ring Gear
   
Result: The starter pinion and flywheel ring gear are OK.
Proceed to Test Step 5.
Result: The starter pinion and flywheel ring gear are not OK.
Repair: Make the necessary repairs. STOP.
   
5. Inspect Engine Accessories and the Transmission (if applicable)
A. Ensure free movement of the driveline.
B. Remove any engine accessories that may lock up the engine and inspect any engine accessories that may lock up the engine.
The following list illustrates examples of engine accessories that may lock up the engine:
1. Hydraulic pump that is driven from the rear gear group
2. Air compressor
3. Engine oil pump
4. Other components that are driven by the engine
   
Engine Accessories and Transmission
   
Result: The engine accessories and transmission are OK.
Proceed to Test Step 6.
Result: The engine accessories and transmission are not OK.
Repair: Make the necessary repairs. STOP.
   
6. Hydraulic Cylinder Lock
A. If an injector has been replaced, evacuate any fluids from the cylinder and attempt to start the engine. Fuel will flow from the cylinder head into the cylinders when a unit injector is removed.
B. If the engine will not start, check for fluid in the cylinders (hydraulic cylinder