Alternators are used in vehicles to charge the battery and to power the electrical system when its engine is running. It's basically an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. The alternator works with the battery to generate power for the electrical components of a vehicle, like the interior and exterior lights, and the instrument panel.Alternators are typically found near the front of the engine and are driven by the crankshaft, which converts the pistons' up-and-down movement into circular movement. Most alternators are mounted using brackets that bolt to a specific point on the engine. Alternators are driven by the serpentine belt which drives all the accessories by means of the crankshaft. Main symptoms of a failing alternator are that most of the electrical components will start to fail and there could also be damage caused to the battery