How to Test Alternator with Screwdriver

How to Test Alternator with Screwdriver

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If you have read most automotive forums, one of the main questions you’re likely to hear is how to test alternators with a screwdriver. In most cases, you might have heard of the voltmeter and multimeter test. But for a screwdriver test, that’s totally a different story. Thankfully, this short guide will discuss everything you need to know regarding testing an alternator with a screwdriver.

You see, an alternator is a very crucial component that supplies power to your auto. It works more like a transformer that transforms mechanical energy into electrical power to keep the car’s components running. But, other than providing power, the alternator does a superb job of charging the battery when the engine is running.

So, with this description, it’s easy to say that the alternator is a very crucial component in any vehicle, boat, train, or truck. In this insightful guide, we’ll look at how to test the alternator using a screwdriver. The best thing about this method is that you don’t have to turn your car on when testing.


What Are the Signs of a Failing Alternator?

Have you ever woken up only to find that your car battery is dead? Well, chances are that you’re dealing with a faulty alternator. From what we’ve seen, an alternator is a special component that’s responsible for charging the battery. Actually, it’s more like a battery charger. So, in case it malfunctions, there are some obvious signs you’re likely to see. Therefore, before we discuss how to test the alternator, I think it’s good if we can begin by looking at those common signs that point to a faulty alternator.

  • Warning Lights: The first obvious sign of a failing alternator is warning lights on the dashboard. In most cases, these lights come in the form of a battery shape to indicate the battery, “GEN” to indicate the generator, or “ALT” to indicate the alternator. If this is what you’re seeing, then it’s time to check the alternator.
  • Dim Light: Another sign of a failing alternator is dimming or flickering headlights. This mostly occurs when you turn on other electrical components. What this means is that there’s an inconsistent flow of voltage or electricity within the car. In most cases, this includes the dashboard lights and the interior lighting.
  • Dead Battery: A dead battery means that the alternator is not doing its job of recharging the battery. Sometimes, the battery might be too weak to start your vehicle in the morning. Now, when it comes to a dead battery, sometimes the issue might not be the alternator but rather a faulty battery. But, to verify the problem is indeed the alternator, the engine might fail to run smoothly which indicates the alternator is not supplying sufficient power to the spark plugs.
  • Buzzing Noises: Lastly, you’re likely to hear unusual buzzing, whirring, clicking, and humming noises when the engine is running. In most cases, these indicate the alternator diode, bearings, and rotor shafts are faulty. It also indicates that the alternator pulleys are misaligned.


How Do You Test the Alternator with Screwdriver?


How Do You Test the Alternator with Screwdriver

At this point, you’re aware of the common signs that point to a failing alternator. Our next step is now to explain how you’re supposed to test the alternator with a screwdriver. The best thing about this process is that it’s quite simple to accomplish. Here, you won’t have to start the engine to spin the alternator just to test it. So, with that said, here are some simple steps you can follow.

Gather Your Supplies

  • Insulating Gloves
  • Safety Goggles
  • Screwdriver

Steps to Follow

  • Step One: Observe Safety

When working on the alternator, you need to note that you’re actually dealing with electricity, which, of course, is dangerous. So, here, you have to keep safety first by wearing protective gear such as insulating gloves to keep your hands safe from mishaps and protective goggles to protect your eyes. Also, you need to ensure the type of screwdriver you’re using is new and not rusted as rust can show false results.

  • Step Two: Insert the Key to the Ignition

Once you’ve set up everything, take the driver’s seat and insert the key into the ignition. Here, you only need to twist the key to open the hood but not to start the engine. Remember, we mentioned that this method does not involve starting the engine for you to test the alternator.

  • Step Three: Open the Hood

With the hood open, get off the driver’s seat and move to the hood. Open it gently and grab the latch on the side to secure the hood safely. Some vehicles have automatic latches that hold the hood securely to give you access to the engine. So, with the hood secured, it’s now time to find the alternator.

  • Step Four: Locate the Alternator

To find the alternator, you need to look for a large coil-shaped device that has a belt attached to it. This belt is the one that links the alternator to the engine. Depending on the design of your car, you might see other belts, gears, and pulleys sitting beside the alternator.

  • Step Five: Now Test the Alternator

To test the alternator, you need to start by placing the tip of the screwdriver near the nuts or bolts of the pulley. Since there’s no electrical magnetism, the tip of the screwdriver will not be drawn towards the alternator pulley bolt.

Now get back to the car and turn the ignition ON where it turns the dashboard lights on and not the engine. This way, you’ll activate the voltage regulator. Next, place the tip of the screwdriver back to the alternator pulley bolt and see whether you’ll feel any magnetic force. At this point, you should feel a very strong magnetic force that indicates the alternator is working perfectly.


How to Maintain Your Car’s Alternator


The best thing about the alternator is that it doesn’t need special care or much maintenance like other components do. However, there are those precautionary measures you need to observe to prevent premature damage to your alternator. Some of these precautions include;

  • Replacing the engine’s protective cover in case it’s damaged. This will prevent water splashes from damaging the engine and the alternator itself.
  • Another protective measure is to fix any oil or fluid leakages as soon as you notice them.
  • Make sure that you cover the alternator entirely when washing your car.


Final Thoughts


How to Test Alternator with Screwdriver Final

As you can see, testing the alternator with a screwdriver is one of the simplest methods you can ever think of. First, the process is simple and secondly, you don’t have to turn the engine on to perform the test. However, in case you turn on the ignition and you notice you’re not feeling any magnetic force, then it means the alternator is faulty. In this case, you need to take your car to an expert mechanic to perform further tests on the alternator.

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