To allow a vehicle to start, and also keep running, electrical power is needed to produce the sparks that ignite the fuel in the engine. When the ignition key is turned, the starter motor receives a current directly from the battery, which starts the engine. Because the electric current is too strong to travel through the ignition switch, a solenoid is utilised by taking in a low current generated by the ignition switch, and then passing a higher current to the starter motor.
Turning the ignition key, supplies power from the battery to a solenoid or relay, the relay switches in and connects the starter motor and coil to the battery. The starter motor is meshed to the clutch flywheel and so turns the engine, kicking off the initial movement of the piston in the cylinder. On release of the key the starter motor stops and disengages allowing the engine to run as normal. The power supplied to the coil is converted to a very high voltage and distributed to the spark plugs via the distributor.
