fan belt 
noun
(In a motor-vehicle engine) a belt that transmits motion from the driveshaft to the radiator fan and the dynamo or alternator.We thought it was the drive pulley for the water pump, which meant it would be a bit of a task to fix, and as an engine without a fan belt means no power-steering, no battery charging, no water pumping, etc....
- One of the important parts of each and every Mazda is the drive belt, or more commonly known as the fan belt.
- If the water pump cannot turn, something might be wrong with the fan belt.