The ignition system creates the spark that ignites fuel and air in a petrol engine. The ignition coil increases 12 volts supplied by the battery to around 20,000 volts. Although older vehicles used a single ignition coil and a mechanical distributor to send the high voltage to each spark plug, most vehicles now have a smaller ignition coil for each cylinder of the engine.
The heating system consists of hot coolant from the engine, a heater core and a blower motor. The A/C system consists of and A/C compressor, condenser. Evaporator core, expansion device and receiver/drier. The heater removes heat from the cooling system and adds it to the passenger compartment. The A/C system removes heat from the passenger compartment to outside the vehicle.
The fuel system is responsible for supplying fuel to the engine so that it can be burned along with the incoming air charge. The fuel pump is located inside the fuel tank, with a fuel strainer normally connected to the inlet of the fuel pump to filter out any debris found in the tank.