What is the most common cause of alternator failure?

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YA

YP Answers

The most common cause of alternator failure is a weak battery. Your car's alternator works very hard to keep your car's battery fully charged, and, if the battery is weak, it can put a great deal of stress on the alternator. The alternator will increase its output to try and keep the battery charged, and this will eventually overtax the alternator and cause it to fail prematurely....Read More

Anonymous

Another failure along those same lines is loose battery terminal connectors and battery terminal corrosive build up. Both create added resistance to stressing the charging system. if you have a serviceable battery keep the water level up to the full mark. Aftermarket battery terminal can also create a high resistance situation depending on the material the terminal is made of.

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SG

Stacey G.

Faulty diode components are one of the most common causes. An alternator has six diodes which convert alternating current to direct current. This in turn powers many electrical systems in the car. High currents and temperatures can damage diodes over time, leading to alternator failure. ...Read More
SL

Silvia L.

The most common cause is when the battery hasn't been fully charged. The alternator can't handle the vehicle's electrics because of the flat battery, so it becomes overloaded, the rectifier blows and the alternator becomes a dud....Read More