This multi-ribbed belt transmits drive from the engine crankshaft to the alternator pulley. It sits in the front-end accessory drive system, routing power to the alternator and any other belt-driven components on that circuit. The belt is constructed with aramid-reinforced tensile cords and a ribbed friction face designed to resist slip under varying load and pulley speed. A worn belt will produce a squealing noise at startup or under electrical load and can cause undercharging of the battery. On replacement, ensure the belt tensioner is within its travel range and that the belt tracks centrally on all pulleys.