Does an alternator squeal when going bad?

Yes, an alternator can produce a squealing noise when it is going bad. This noise is often caused by worn-out or loose belts, bearings, or pulleys within the alternator. As these components wear down, they can start to vibrate and cause a high-pitched squealing sound. Additionally, if the alternator's voltage regulator fails, it can cause the alternator to overcharge the battery, which can also produce a squealing noise. If you hear a squealing noise coming from your engine compartment, it is important to have your alternator inspected by a qualified mechanic to determine the cause and prevent further damage to your vehicle.