Why would your fan belt and alternator belt stop turning and the engine still running?

1. What would cause a serpentine belt not to turn?
2. Does fan belt affect alternator?
3. Why would an alternator seized?
4. What are the signs of a bad belt tensioner?
5. What happens if you over tighten alternator belt?
6. What kills an alternator?
7. What is alternator ripple?
8. What can damage an alternator?
9. How do you know if your alternator pulley is bad?
10. Should an alternator pulley spin freely?

What would cause a serpentine belt not to turn?

It is likely that one of your ribbed or slotted pulleys has seized up causing your belt to be unable to spin. ... It is possible that the seized pulley could have caused damage to the pulley or the crankshaft alignment key which may have caused the pulley to break.

Does fan belt affect alternator?

As the alternator or serpentine belt is powering the alternator, it will, of course, cause the alternator to struggle when the belt is loose. There is a battery warning light on your dashboard in most car models, which will light up when there is a problem with the charging system.

Why would an alternator seized?

Alternators have moving parts, get dirty and are subject to stress from heat and cold. As a result, the internal parts gradually wear out. One of the most common failures is bearing failure. ... When the bearings fail, the rotor will not spin efficiently and can eventually seize.

What are the signs of a bad belt tensioner?

One of the most common symptom of a bad or failing drive belt tensioner is noise from the belts or tensioner. If the tensioner is loose the belts may squeak or squeal, especially when the engine is first started.

What happens if you over tighten alternator belt?

Dear Anthony: A belt should never be over-tightened. ... An over-tightened belt can burn out any bearing that the belt rotates on, including alternator, power steering pump, A/C compressor, idler pulleys, etc. An over-tightened timing belt can ruin any pulley bearing it is connected with.

What kills an alternator?

Running in full charge mode continuously can kill an alternator, so trying to have your new alternator try and charge your dead battery can result in immediate alternator failure.

What is alternator ripple?

Rabble-Rousing Ripple

Diodes rectify the stator's AC current into DC. Although this happens, a small AC voltage still appears at the alternator's output terminal. When properly displayed on a scope screen, this AC voltage has a rippled appearance; consequently, it's called alternator ripple.

What can damage an alternator?

There are two types of alternator damage: mechanical or electrical. The former is a failure of fasteners, bearings. The latter is a winding rupture, diode bridge defects. Weak headlights, difficulties when starting the engine, a sensor signal: all these symptoms signalize of problems with the alternator.

How do you know if your alternator pulley is bad?

If you ever hear growling or whining noises coming from under the hood, you could have alternator problems, which should be checked out by a professional ASAP. This growling or whining sound happens when the belt that turns the alternator's pulley becomes misaligned or rubs against the side of the pulley.

Should an alternator pulley spin freely?

It should turn quite easily but more important is it should be smooth. Very smooth. New bearings will sometimes feel a bit stiff and not turn freely because of the new seals and new grease that is in them. However that is ok as long as they are smooth.