The alternator is a simple car component, yet it plays a critical role in the operation of your Toyota vehicle. It is a small electrical generator that converts the mechanical energy to electrical energy through alternating current. The alternator provides power to a range of parts and systems and also keeps your battery charged throughout the day. Your car might need an alternator replacement when you notice your battery is constantly dying. If you know your battery is in good health, the explanation likely lies with a faulty alternator. Another thing you might experience are electrical systems having issues performing as well as they used to. The lights on your dashboard or your headlights might start to flicker or dim. When you need a replacement, you need to buy an OEM Toyota alternator that will fit your car perfectly.