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5 Causes of alternator not charging

November 4, 2017 | Electrical Repair Info

The main function of an alternator is to generate electricity for the electrical components of the vehicle and to charge its battery. The alternator produces this electrical energy by converting the mechanical energy. If you were to try and start your vehicle without an alternator, the battery power alone would not be able to produce enough electricity to get the engine running. If you had a new car battery and were lucky enough to turn the engine on, it would probably run for about 10 minutes before all the electricity shuts off. The alternator is needed to keep the battery recharged and to alternate the electrical current throughout the electrical components of the vehicle to keep them powered.

The Top 5 Causes

A lot of people get confused when they begin to have electrical problems with their vehicle. It is easy to misdiagnose these problems as being a bad battery versus a bad alternator. To understand the difference, you must learn about what causes an alternator to stop charging. Then, you can inspect the vehicle and determine if it is the alternator that is causing the power problems in your vehicle.

Below are the top 5 causes of an alternator not charging.

  1. Computer Error – Most people are driving cars that were made within the last 20 years. These newer cars all have a central computer system which manages and operates the vehicle’s components and parts. The computer even manages the alternator as well. Therefore, all it would take is for there to be a computer error and the result would be a malfunctioning alternator. Then it would not be able to charge.
  2. Broken Belt or Pulley – The belt and pulley of the vehicle are what produces the mechanical power that gets converted into electrical energy by the alternator. The belt can easily break if it gets stretched out too much and snaps apart. The pulley can also get damaged after a while as well. In either case, the alternator will no longer be able to produce a charge for the battery.
  3. Blown Fuse – There are certain model cars which have alternators that depend on a particular fuse to operate. However, these fuses can blow if there is a power surge or simply from old age. Once that happens, the alternator will no longer charge the battery. Not all vehicles have these fuses, so you will have to check your owner’s manual to see if your car has them. If so, then this is worth investigating in the event that your car battery is not being charged.
  4. Wiring Issues – There are numerous wiring components in a vehicle which produce power for the alternator. All it would take is for one wire to be disconnected or cut and then no power would be generated for the alternator. As a result, the alternator won’t be able to charge the battery.
  5. Bad Alternator or Battery – Alternators and batteries do not last forever. They each have their own lifespans, though. A car battery will last from 2 to 5 years, depending on how often you drive and how cold the temperatures are where you live. Batteries last longer in colder environments and shorter in hotter environments. Alternators last about 7 years or every 80,000 miles.

Read also: The Difference between Supercharger VS Turbocharger and Pros Cons

How to Fix

The most common reason for an alternator not charging a battery is because of a bad alternator or battery. You can easily test the voltage by connecting a voltmeter to your battery while the engine is off. The voltage of the battery should be between 12 and 13 volts. If it is lower, then you can automatically assume there is a battery problem. Otherwise, start the vehicle and get the engine up to 2,000 RPM. This will put a lot more demand on the alternator. If the voltmeter shows the voltage decreasing while you do this, then you have an alternator problem.

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