What Causes An Alternator To Fail?

This article may contain affiliate links. For details, visit our Affiliate Disclosure page.

What Causes An Alternator To Fail

Alternators are not designed to last forever. They have a lifespan and when the time comes for them to fail, there may be no warning signs. Many people are unaware of what causes an alternator to fail in the first place. This article will give you some insight into this issue so that you can prepare yourself for it happening to your vehicle.

What is an Alternator?

An alternator is a device that produces electricity. The electrical current can be used to power other components in the car, or for use by external devices like dashboards and radios. An alternator’s lifespan will depend on how often it has been used and its overall condition.

What Causes an Alternator to Fail?

The Alternator Can Fail When:

  • The belts that carry power to your car’s engine are damaged.
  1. Built-up corrosion can cause an alternator to overheat which leads to its eventual failure.
  2. Electrical wiring problems will lead to a short that causes electrical malfunction or damage in the alternator.
  • An error in computer systems that can’t control electrical systems.
  • A fuse failed leads to a failed alternator.
  • Your alternator is dead and needs to be replaced.

There are many reasons for an alternator to fail. Here are the most common ones that are told by auto experts.

#1 Broken Belt

The most common factor that leads to an alternator failure is a belt that has worn out and needs to be replaced, which can cause the belts in your car’s engine compartment. This is an easy fix for someone who knows how to work on cars or with simple tools.

The belts are what carry power to your car’s engine, and without them an alternator can’t produce electricity.

The reason for the belt wearing out is usually related to age or excessive wear from a loosened bolt that causes it to slip.

Replacing belts should be done every 60-75K miles on average, so if you’re nearing this, be aware that it could cause your alternator to fail.

In some cases, there can be other factors that lead to a belt not working effectively or at all. This is usually due to the engine overheating or bending when going over bumps in the road which will loosen and break belts as well as potentially damaging an alternator’s pulley system upon contact.

#2 Built-up Corrosion

Alternator failure may also happen because of corrosion build-up in the alternator from moisture leaking into it. This built-up corrosion can cause the alternator to overheat which will lead to its eventual failure.

Alternators are not made for long-term use and can fail if they have been used excessively due to age or wear on the part of the belt, as well as moisture build-up from leaking water into it.

#3 Wiring Problem

Another reason that causes the alternator to fail is the wiring problem. When the alternator is not grounded properly, it will lead to a short and this can cause an electrical malfunction or even damage the alternator.

Or if one of the wires is damaged or corroded, the alternator will not function properly and it may stop working.

Alternators are either belt-driven or self-powered by electromagnets on their own which creates an electric current that generates electricity for your vehicle’s battery.

#4 Computer Problem

Another thing that can cause your alternator to fail is a computer problem. When the computer has an error, it will not be able to control some of the electrical systems and this may stop working as well.

Is The Higher Amp Alternator Better?

Some modern car models are designed with computer systems like Electronic Control Unit (ECU). These computer systems monitor the engine, transmission and other electronic components.

The ECU decides when to use the battery power or alternator with a switch. If there is an error in the electrical system, this may cause your vehicle to stop running without any warning lights coming on that indicate something needs fixing.

#5 Fuse Problem

A fuse problem may also cause your alternator to fail. The fuses are used on the vehicle’s wiring system and play an important role in running different electrical components.

If there is a fault with one of these, it will affect other systems like the battery or alternator which would be unable to work any longer until you have fixed the problem.

#6 Dead Alternator

This is a very obvious reason for your alternator to fail. A dead alternator means that when the battery is charged it can’t be dispersed and run through the car’s electrical system as needed.

This would then cause other parts of the vehicle, like headlights or radios not to work properly because they are running off this power source.

An alternator normally lasts between 50,000-100,000 miles and will need replacing if it has failed.

Final Words

There are various reasons that could lead to a failure in the alternator. Mechanics suggest we use a bench test in order to see if the alternator is working as it should.

If you are experiencing a vehicle with an always dead battery, then this might be time to check your alternator.