An integrated starter/generator (ISG) assembly is often found mounted to your car's engine. A belt-driven alternator/starter was designed in order to meet your car's electrical demand due to creature comfort features like A/C, stereo or heated seating.
The drive belt on an alternator is connected from your car's alternator pulley to the engine's fan. To keep the alternator's rotor turning to generate electricity that flows to the car's electronic control modules, the drive belt rotates the pulley at the fan's pace.
If your car is squealing as you turn on the A/C or as you move your seats, then the noise may be caused by a cracked, damaged, loose, or worn drive belt. Even the belt's undercore may be broken or peeling off. Damage on the belt's ribs are the most apparent.
If the drive belt checks out, you will want to adjust the belt tension to the specifications set by the manufacturer. Use a hand-held tension gauge. On some cars with spring-loaded serpentine belts, the tension is indicated by indicator marks on spring-loaded tensioners.
