An alternator is a device that converts mechanical energy to electrical energy. In a vehicle, the alternator is responsible for recharging the battery and providing power to the electrical system. A properly functioning alternator is essential for the reliable operation of a vehicle.
There are a few simple tests that can be performed to check the working condition of an alternator. One common test is to measure the voltage output of the alternator. This can be done with a voltmeter connected to the battery terminals. The alternator should be outputting between 13.5 and 14.5 volts when the engine is running.