Do you think you might need a new Isuzu alternator? If you're unable to get your engine to turn over, it may be time to replace the alternator. Your battery will only be able to maintain its charge for a few minutes if your alternator is bad. Other essential parts of your vehicle that will not function without the alternator are the engine fans, the lights, and the ignition coils. Many people notice their auxiliary lights dimming right before their alternators stop working completely. The stereo and air condition will also stop running when the alternator breaks. There are many ways the alternator can break. Whenever any of the four major parts of the alternator: the rotor; stator; voltage regulator; and diode packs go bad, you have to buy a replacement alternator. You may get luck and realize that it is just the alternator belt that is broken. If that's the case, you can replace that piece without having to install a whole new alternator.