The ignitor coil, also known as the spark coil; is found in every vehicle's ignition system. This ignitor coil is used to take a low voltage and create it into a thousands of volts; which then create the electric spark that is needed to ignite the fuel of the vehicle. Depending on the vehicle, some coils come with an resistor, while other coils work with a resistor wire; and some resist on an external resistor, which helps in limiting the currents flow. There is a wire that goes from the distributor to the ignition coil; and then there is a high voltage wire that goes from the distributor; to each and every spark plug. Once the spark has lit, the process of combustion begins. The main task of the ignitor coil is to help the vehicle start, as without it; the vehicle would not be able to start these ignition systems are not used in diesel engines, as they completely rely on compression; which helps them to ignite the air and fuel mixture to start combustion.