How does a serpentine belt power an alternator?

How does a serpentine belt power an alternator?

As this picture illustrates, a single serpentine belt will typically power all externally mounted accessories. Idler pulleys help with proper routing of the belt. Unlike individual belts, tension on a serpentine belt is provided by a tensioner pulley which is under constant spring pressure.

What happens when you change the serpentine belt?

Billions of rotations under constant tension of the serpentine belt will take its toll over time. The “ribs” in the pulleys get damaged so even if you change the belt, the damaged pulley will tear and shred the belt again.

What causes a belt to squeak over pulleys?

Squeaking is caused because the belt is slipping over the pulleys. The slipping is caused because the belt loses ability to produce enough friction between itself and the pulleys (mostly due to material fatigue).

Is the water pump driven by the serpentine belt?

Another important device driven by the serpentine belt is the water pump. This is not always the case as on a lot of cars the water pump is driven by the timing belt. You should have this in mind so you don’t falsely “accuse” the serpentine belt for overheating.

What kind of pulley does a serpentine belt use?

Determine if there is a belt tensioner pulley. Depending on the application, your serpentine belt will either have tension placed on it using a movable bracket or an auto tensioner pulley. This pulley uses an internal spring to apply consistent pressure to the belt at all times.

Is the alternator pulley allowed to spin one way?

The alternator pulley has a sprag clutch inside that allows it to spin one way, but not the other. This video shows how to test yours. After watching the video, I went out and tested mine.

How do you tighten a serpentine belt on a car?

If your vehicle does not have an auto tensioner, insert a pry bar or piece of wood between the alternator and the engine. Run the belt over the alternator pulley, then use the bar to pry the alternator away from the engine and increase the tension on the belt. Tighten the bolts again as you apply tension.

What causes a serpentine belt to get stuck?

The main reason, in most cases, will be a stuck pulley from one of the devices (alternator, AC compressor, power steering pump etc) or a tensioner. A stuck pulley is mostly caused by a worn out bearing. The belt slides over a motionless pulley causing extensive friction, heat and the recognizable sound.