How to Test A Car Amplifier with A Multimeter – A Beginner Guide

A digital multimeter can test most electrical equipment from capacitors to transformers or any electrical circuit or component connected or not. There are various tests you can carry out on these pieces of equipment. Do you, however, know that you can also test a car amplifier?

What is Multimeter?

A multimeter is a device that measures electrical currents. There are two types of multimeters, one is called analog multimeter and the other one is digital multimeter. You can use them to find out what is going on with your home, business, or other electronics.

What is the best low budget Multimeter?

What is the best multimeter for low budget. This is a question that many people that are interested in purchasing one have asked. You may have seen multimeters in amazon or in electrical shops, but you may not understand what they are and why you need to use one.

Before you buy a multimeter, you should know the answers to these questions. Then you can shop wisely and find the right product for your needs. If you are an electrician the definitely you will need digital multimeter.

What is a Car Amplifier and How to Test it?

How to Test A Car Amplifier with A Multimeter

A car amplifier is a device that amplifies the audio output from a car’s stereo system to a more audible sound. They work o a type of internal power that powers the amp’s circuitry with a higher power.

They take audio signals then deliver them to speaker terminals for you to hear the music from the car’s stereo. Without amps, it would not be easy to hear loud music in cars and other vehicle types.

Car amps usually have a 12v power supply in them. The voltage is generally stepped up to power higher voltage to the transistor stages responsible for the output.

The (+ve) positive wire of an amplifier is usually wired to the vehicle’s battery with a fuse. The battery is the source of all the current in the whole vehicle.

 In most cases, the ground (-ve) wire is attached to a clean metal attachment on the body. This is because a vehicle’s wire cannot usually support the full amount of current required by an amp when it is in heavy use.

Now that you know what an amplifier is let’s get down to how you can test it.

Testing a Car Amplifier with a Digital Multimeter

Testing a Car Amplifier with a Digital Multimeter

The first thing you will have to do is locate the position of the amplifier. You can’t run a test on something you can’t see. Your car’s manual should help you know where it is. It can be almost anywhere, depending on the type of car you own.

The best multimeter for home use under 100 will help you easily check and test an amplifier.

Step 1 – Test For Voltage

The first thing to do is to set the multimeter to test for voltage. Locate the voltage dial and turn it on.

If you are using a manual ranging multimeter, set the ranger a value higher than 12v. If it is an automatic ranging multimeter, you won’t have to do that.

Now check whether the amplifier is on or not. You will do this by checking the voltage of the amplifier’s fuse.

Step 2 – Connect the Wires

Connect the multimeter’s test leads to the two wires of your multimeter. The black lead should be on the negative wire, and the red test leads on the positive wire of the amplifier.

Step 3 – Check The Front End Display

If after connection you see nothing on the display, it will mean the amplifier is defective. If you see a value on the multimeter’s display, then the amplifier is still in good condition.

At times the amplifier will send out varying values, which means it is more likely to cause distortions when in use.

If the multimeter goes off when checking the voltage, it will mean the voltage source has issues.

How Multimeter Work?

In general, a multimeter can work in two ways. You can either use it as a signal meter, or as a display meter. Some of the features that you can find on a multimeter include alarms, over current alerts, temperature controls, current detectors, and so much more.

If you can think of a product that these features can help with, then you can probably see how useful a multimeter can be.

What Multimeter Powered by?

One of the most important questions you should ask before you buy a multimeter is what it is powered by. You will need to be able to operate the multimeter from batteries, if you intend to use it in a commercial setting.

There are also some multimeter available that are powered by solar power. They are great for people that work at home or who are interested in purchasing an instrument that can be used in a variety of places. If you want something simple, then a battery powered multimeter is probably the way to go.


Some products offer warranties. If you want to make sure that you get your money back in case something goes wrong, you may want to consider this option. It is easy to find out if there is a warranty for the multimeters that you are considering.

If there is not a warranty, then there is no reason to buy them. Whatever you do, don’t ever buy a multimeter that is not rated for the voltage levels that it will be working with. That can be dangerous.

Final Thoughts

That’s how to test a car amplifier successfully. As you could see, it isn’t as complicated as it might seem. A multimeter will help you test almost anything provided it runs on electricity.

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