The battery supplies the power necessary to start the engine when the ignition switch is is turned on.

The intake manifold distributes outside air to the intake ports on the cylinder heads. The intake air filter removes any airborne contaminants before the air enters the engine.

The radiator is responsible for tranferring heat from the coolant to the outside air. Radiator hoses transfer coolant to and from the engine to the radiator and a radiator cap maintains pressure in the cooling system to increase the boiling point of the coolant mixture and thus allow it to absorb more heat.

Spark plugs receive current from the distributor and use it to spark combustion in the combustion chamber of a cylinder.

The transfer case splits engine power between the front and rear axles of four-wheel drive vehicles.