The lead-acid battery is the core of the electrical system, providing current to the ignition system to start the engine as well as delivering supplemental current when the alternator can't handle high electrical system loads and acting as an electrical reservoir for excessive current.

The crankshaft converts the reciprocating motion of the piston into the rotational motion that's used to power the vehicle and its components.

The stroke cycle of an engine is governed by the crankshaft which serves to regulate the firing order of the cylinders. All cylinders are not on the same stroke at the same time and correct firing order is important to balance engine operation and minimize vibrations. A common firing order for four-cylinder engines is 1-3-4-2 which indicates that cylinders 1 and 3 fire (power stroke)together and cylinders 4 and 2 fire together.

The lighting system consists of interior lights, instrument panel lighting, headlights, and taillights. Like household electrical circuits, the vehicle's lighting system is protected from current spikes by fuses and circuit breakers.

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