How To Test Car Alternator Using Multimeter

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Nothing is worse than having a faulty or dead alternator. You might be wondering if there’s a way to find out about a faulty alternator before it goes completely useless. Well, I have good news for you! The main thing that is required is the multimeter, which if you don’t have then don’t worry as you can easily find the best multimeter under 50 or less online.

If you are unable to start up your car then that doesn’t mean that you have a faulty alternator because there are other components in a car that may have a similar outcome. For example, a dead or loosely fitted car battery and bad relay or starter. If all of them are in good condition then lastly comes the bad alternator. However, it is not crucial for someone like you to learn all the mechanism and science just to test car alternator but you should be able to know the basics.

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How To Test Alternator

So, below you are going to see how to test your alternator. If you get stuck at any step, then don’t hesitate to drop your problem in the comments section so that we can help you. Before we begin, make sure you have the following list of tools: Rubber Hose, Multimeter, and Wheel Chocks.

  • The first thing you should do is park your car at a smooth perfectly leveled surface.
  • Grab the wheel chocks and place them on the back side of the driver side.
  • Make sure the engine is turned off and then open the hood of the car.
  • Now, you will need to find the alternator. Most probably it is going to be on the front of the engine and around the top side.
  • Make sure to check the engine’s belt and if it is loose then tighten it.
  • Fire up the engine and see if it makes any strange squeaky sounds.
  • Grab that rubber hose that we talked about earlier and place it on the alternator case while the opposite end to your ear. This will help you easily find squeaky sounds.
  • Now comes the main part. Turn off your engine and grab the multimeter.
  • Set multimeter to DC volts and place the positive and negative ends of the meter on the battery appropriately.
  • Turn on the engine and observe the reading on the meter. The minimum volt that it should show is 13 volts because a good condition alternator outputs around 13 to 14 volts.
  • Lastly, you should not forget to stress test the alternator by adding some load like turning on the headlights, music player, LCD screen, or air conditioning. If it maintains a steady number of around 13 volts then it is good shape and if it crosses 15 volts then you might want to replace your alternator.

So, these were just few ways to find out if you have a faulty alternator or not. If your alternator passes all these tests then you don’t need to worry about your alternator anymore and if not then consider talking to a professional mechanic that will help replace your alternator.

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