How to troubleshoot the engine crankshaft does not rotate and the engine cannot start when the Cat 320C excavator start switch is turned to the ON position

1. When the start switch is in the ON position, the engine crankshaft does not rotate. The possible causes and solutions are as follows.
(1) The battery output voltage is low. Check battery condition. Charge or replace the battery if necessary.

(2) The wire or switch is damaged. Repair or replace parts if necessary.

(3) The electromagnetic coil of the starter is damaged. Install new solenoid.

(4) The starter is damaged. Repair or replace starter.

(5) The engine crankshaft cannot turn due to internal problems. Disconnect the drive unit. If the crankshaft won't turn, remove the injector and check for fluid in the cylinder while turning the crankshaft. If it is not the problem of fluid in the cylinder, the engine must be disassembled and checked for other internal problems in the engine. Possible internal problems include seized bearings, seized pistons, improperly installed pistons in the engine, etc.

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2. The engine cannot be started
The possible causes and solutions are as follows.
(1) There is no oil in the fuel tank. Fill the fuel tank.

(2) Fuel quality is poor. Drain the fuel from the fuel tank and install a new fuel filter element. Fill the fuel tank with high-quality fuel.

(3) The fuel filter is too dirty. Install a new fuel filter.

(4) The fuel line is broken or dirty. Clean or replace fuel lines if necessary.

(5) The fuel pressure is too low. Replace fuel filter. Check that the bypass valve moves freely. Install a new bypass valve if necessary. (6) There is air in the fuel system. Find the leak in the fuel system and fix the leak. Remove air from the fuel system.

(7) Fuel injection timing error. Adjust injection timing if necessary.

(8) The fixed discharge valve is open (the fuel pressure is insufficient to start the engine). Replace fixed bleed valve.

(9) The startup speed is slow. Check battery condition. Replace the battery if necessary. 

(10) There is no fuel in the fuel injection pump housing. Use the fuel priming pump to charge the fuel injection pump housing with fuel.