Engine, Electrical and Mechanical Systems
Propulsion systems
Understand the basic operation of diesel engines: air intake, compression, fuel injection, combustion and exhaust. Know the cooling circuits, lubrication system, fuel system and starting system. Learn the checks before starting and the checks after starting, including oil pressure, cooling water flow and exhaust colour. Understand common faults: air in the fuel line, blocked filters, overheating, and contaminated fuel.
Electrical systems
Know the difference between AC and DC systems, battery types, charging, and the purpose of fuses and circuit breakers. Understand earthing, isolation and the dangers of shore power connections. Learn basic fault-finding: a circuit that fails at the fuse, at the switch, or at the load.
Mechanical systems
Understand steering systems, gearboxes, shaft seals, and the importance of regular inspection. Know how to isolate fuel and electrical systems in an emergency.
Traps
- Assuming an engine that cranks but does not fire has an electrical fault.
- Ignoring black exhaust smoke as a sign of overloading or injector problems.
- Using the wrong fuse rating.
- Forgetting to close the fuel valve before maintenance.
Worked rule of thumb
For any engine fault, check in order: fuel, air, compression, then electrical. Most no-start faults are fuel or air related. For any electrical fault, check the fuse, then the switch, then the load.