Electricity is essential for any vehicle. It ensures the operation of the engine, lighting devices, the internal combustion engine ignition system, etc. Passenger cars use 12V constant voltage, while trucks need 24V. The standard automotive electrical circuit includes a battery, an ignition switch, a starter and a generator, which powers all the consumers and recharges the battery. The automotive electrical equipment can be subject to various malfunctions, and the source and any energy consumer can fail. The electrical equipment of a modern vehicle is rather complex, and its repair requires knowledge and special skills.