A Chevrolet serpentine belt diagram shows the route the engine drive belt takes around the accessories it controls. Typical diagrams are unlabeled, merely showing shapes representing the affected pulleys, although some examples do show the pulley names.
Serpentine belts, also called engine drive belts, replaced multiple v-belt systems with a single belt winding through accessory pulleys. The diagrams provide information on how to correctly thread a belt at replacement. Diagrams are located in operator manuals and on plates near the engine block.
The serpentine belt routes reflected in the diagrams vary by which accessories a vehicle includes. Most cars and trucks have pulleys driving a generator assembly, water pump, power steering pump, cooler pump, air conditioning compressor assembly or idler. Older Chevrolet vehicles may not have air conditioning, eliminating the air conditioner compressor pulley. They often have air injection reaction pumps with the related pulley not seen on newer models. Cars with General Motor's 3.8-liter engines have two serpentine belts, an inner belt to run the supercharger and an outer belt to run most accessories.
A serpentine belt's tension is controlled by a tensioner pulley, another part of the belt route shown on the diagram. The crankshaft or harmonic balancer minimizes vibration and acts as another control mechanism on the serpentine belt route.