In addition to the battery, there are two other components to your vehicle's ignition system. And these two components must be in good working order for your vehicle to start and run properly. Starter. When you turn the ignition key, you are actually turning on the starter, which then cranks the engine. When a starter isn't working correctly, the engine may start with great difficulty, or not at all. Starter problems may be due to electrical/mechanical failure, or outright breakage. Alternator. The alternator carries out two important tasks. It recharges your battery while the vehicle is running to keep it at peak starting power. The alternator also works with your battery as a team to operate electrical components, such as headlights, windshield wipers, and more. A malfunctioning alternator can cause electrical components to operate erratically, or even cause your engine to suddenly stop running.