• LEARN
  • GUIDES
  • HOW TO
  • REVIEWS
  • Menu
  • Skip to right header navigation
  • Skip to main content
  • Skip to primary sidebar

Audio In Car

Car Audio for Beginners

  • LEARN
  • GUIDES
  • HOW TO
  • REVIEWS
Ways of Testing a Car Amplifier with a Multimeter

Easy Ways of Testing a Car Amplifier with a Multimeter

By: AIC-Team | Last Updated: October 31, 2022 | This post contains affiliate links.

Are you and your friends planning a road trip, but you don’t have loud music in your car?  Worry no more. All you need is to get a good amplifier for your car’s sound system.

However, you can’t just settle for any amplifier without checking it yourself. No matter how famous the brand is, don’t just trust blindly, no matter how good the deal is. The best amplifier in the market today is Rockford Fosgate R500X1D Prime 1 with its music output I highly recommend it.

Post Contents

  • Parts of an amplifier
    • 1. Power
    • 2. Input
  • What is a multimeter?
    • There are two types of multimeters
      • 1. Digital multimeters
      • 2. Analog multimeter
  • How does a multimeter function?
  • Steps of checking your amplifier with a multimeter
    • 1. The multimeter
    • 2. Testing the amplifier
      • Find the amplifier’s location in your vehicle
      • Test the fuse of the car amplifier for power
      • Check the amplifier protection mode
      • Verify the output
      • Check the signals of your amplifier
      • Check the voltage coming from your amplifier
  • How do you know your amplifier has terrible ground?
    • 1. Overheating
    • 2. Clipped sound signal
    • 3. Unable to turn on
      • Factors that lead to an amplifier’s failure to turn on are:
    • 4. Restarting all the time
      • Factors that cause a continuous switching on and off of an amplifier are:
    • 5. Whining noise
    • 6. Burning or fire
  • How to Fix Your Car Amplifier?
    • 1. Gather the appropriate tools
    • 2. Remove the wiring
    • 3. Check the connections of the amplifier
    • 4. Test the connections
    • 5. Inspect the amplifier
    • 6. Reconnect the wires
    • 7. Check the transistor
    • 8. Turn down the gain
  • Precautions:
  • Conclusion

Parts of an amplifier

An amplifier has three parts:

1. Power

It comprises the 12V power wire that originates from the battery, the ground wire connected to the chassis ground, and the remote turn-on wire that turns the amplifier on depending on if the small wire has 12V on it or not.

If your amplifier has the correct 12V and ground but will not turn on, you should check the remote wire and fuses.

2. Input

Your input signal generally originates from low voltage RCA wires. This is because your amplifier only requires a small amount of sound signal so that it has headroom to clean it up, process it, and expand it with minimal distortion possible.

Also, some amplifiers have a high input option. These amplifiers generally don’t deliver the most amazing audio.  They frequently introduce a higher amount of distortion into your sound system.

One method of testing an amplifier to see if its input is working is by using headphone jack to RCA inputs like Monoprice Audio Cable – 3 Feet

To do this, plug your phone into the headphone jack and play music while your amplifier is on. If you don’t hear audio, your amplifier might have an internal defect.

Checking your car amplifier is not a challenging task. You only require a multimeter to see if it is working.

What is a multimeter?

Car owners are completely unaware of electronics related to their car’s sound system.

Don’t worry anymore if you are one of them because we will explain it to you. Multimeter’s work is to troubleshoot electric and electrical devices. The multimeter can measure resistance, current, and voltage in an electric or electronic circuit.

Technically a multimeter is used to check the proper operating levels.

There are two types of multimeters

Digital multimeter

Analog multimeter

1. Digital multimeters

Digital multimeters are popular since they are more user-friendly and indicate results in digits, thus reducing errors while reading results.

The best digital multimeter is Innova 3300 Hands-Free Digital Multimeter 

2. Analog multimeter

Analog multimeter  use a needle along a scale. They are affordable but are hard for beginners to read the results correctly, especially on resistance scales.

The best analog multimeters in the market are Tekpower TP8260L Analog Multimeter With Black Light and Transistor Checking dock.

Each type of multimeter has its advantages and disadvantages. Therefore it will be upon you to choose the one you can work with.

How does a multimeter function?

A digital multimeter features two types of leads.

Red and black. Red is supposed to be correctly connected to the voltage, current, or resistance and considered a positive (+) terminal.

In contrast, black should be connected to a common or ground port and considered a negative terminal (-).

The multimeter also has probes used to hold the tested connections.

Moreover, there are tips used technically to offer a connection point.

Most of the time, your amplifier’s connection could be proper, but it still doesn’t work.

Therefore, you should use a multimeter to test your car amplifier properly.

Also, it is highly recommended your turn off the power before connecting the meter.

Steps of checking your amplifier with a multimeter

The task could sound very challenging to some, while to others, it is not.

However, we will divide the task into two to make it easier.

  • The multimeter
  • The amplifier

1. The multimeter

First, you need to check if you have a multimeter. It would help if you buy a good quality multimeter. You can easily purchase a multimeter from any electronic shop, or you can get it online but always choose the best like Astro Multimeter 2000 Counts Digital Multimeter with DC AC Voltmeter and Ohm Volt Amp Tester  It Measures Voltage, Current, Resistance; Tests Live Wire etc.

Secondly, after buying a multimeter, do the configuration of your multimeter. This involves rating the meter according to the number of amperes passing through the circuit most of the time.

The circuits have a nameplate where the approximate maximum amperes are displayed, and on the multimeter, maximum handled amperes are also seen. Therefore, do not go for more than the indicated amperes of the multimeter.

Due to this, first, do the configuration in the following steps:

A multimeter comes with VDC (Voltage Direct Current) and VAC (Voltage Alternating Current).

The VAC combination is crucial when testing appliances running from your house supply.

In comparison, the VDC mode is vital when testing a car amplifier, so you have to set the amplifier at VDC mode, which runs directly.

After configuring the multimeter, the next step is to set the wires. Like mentioned above, there are two types of cables.

  • Black and red

Black is typically called the ground wire and is considered the negative terminal, whereas red is the amperage wire.

It would be best to plug the black wire in the standard circuit and the red wire in the socket with label A (amperage).

  1. There is a central dial in your multimeter that, when rotated, you can set your amperage.

Set the provided amperage setting by rotating the central dial in line with the socket.

2. Testing the amplifier

After you configure your multimeter appropriately, you can now use it to test your car amplifier.

You can test your car’s amplifier by following these steps:

  • Find the amplifier’s location in your vehicle

If you are testing factory-installed amplifiers like in most scenarios, cars come with preinstalled amplifiers, and their location may vary depending on the car model or company. Therefore, the first thing you should do is find the mount location of the amplifier

You might find car amplifiers behind the seats, on the dashboard, or elsewhere.

The car’s manual will help you find the exact location of your in-built amplifier.

  • Test the fuse of the car amplifier for power

To do this, check the fuse voltage attached to the amplifier.

  • Check the amplifier protection mode

An amplifier has a protection mode, just like a shutdown state.

Your amplifier goes into the protection mode to save it from any worse damage, even if it is annoying.

An amplifier goes to protection mode because of incorrect installation, improper wiring connections, or if the amplifier has an internal defect.

Therefore, you must check the amplifier by disconnecting all the connections and switching it on.  If the protection mode is on, then there is a problem.

Connect an amplifier with the multimeter and check the wiring problems by studying the voltage coming from the wires connected to the car amplifier.

  • Verify the output

Plug the multimeter wire into the output channel to check the output frequency.

Check the reading on the multimeter. If it does not indicate any task, it means the output has failed. Your speaker has blown.

  • Check the signals of your amplifier

Attach the multimeter with the amplifier to check the amplifier’s signals.

If the amplifier signals are reducing, it means the amplifier will cause distortion.

  • Check the voltage coming from your amplifier

Attach the amplifier with the multimeter and check its voltage.

You must check the voltage source if the amplifier goes off.

There could be another scenario where your amplifier shows a voltage of fewer than 10 Volts. In such a case, you could damage your amplifier, and it is good to have a technician look at it.

Also, sometimes the amplifier you are currently using could have lousy ground, which could cause your problems.

How do you know your amplifier has terrible ground?

1. Overheating

Overheating an amplifier happens when the amplifier’s linkage is faulty or if the ground or wiring is too short. This occurs since the amplifier is not receiving enough voltage to give the desired output.

To offer uttermost grounding, ensure that your ground wire is almost the same accurate size as the power wire and is fixed firmly to a part of the frame that has been scoured free from any paint and sanded down.

The most common reasons for an amplifier overheating are:

  • Improper installation.
  • Poor construction quality.
  • Mismatch in impedance.
  • Insufficient power.
  • Improper ventilation.
  • Some amplifiers could be clogged.

The efficiency of an amplifier gives a hint on the quantity of power supplied to it,  transformed to sound signals, and the amount lost as heat.

2. Clipped sound signal

Clipping begins in the form of resonance when an amplifier is required to deliver more power than it is capable of. It is a characteristic of poor grounding.

When you push an amplifier further from its capabilities to create enough power to replicate the input signals to the speakers( for example, due to a mismatch of impedance), it will be tough to magnify the input signal without reducing the quality of the initial signal. The signal will be amplified but in a badly distorted manner. This will affect the audio quality and put your amplifiers in danger of being destroyed by clipping.

Other factors that cause clipping are:

  • Low wire gauge.
  • Extremely high input sensitivity.
  • The need for a bigger alternator.
  • The source signal is over-equalized.

3. Unable to turn on

An amplifier that won’t turn on is another sign of bad ground. If the circuit that powers your amplifier is completed by grounding, an amplifier with the lousy ground will not turn on to begin with.

However, the ground cables and power must be very thick to satisfy the amplifier’s electrical current’s needs.

Otherwise, the amplifier will not turn on or not function properly.

Factors that lead to an amplifier’s failure to turn on are:

  • Absence of remote.
  • A blown a fuse.
  • Poor grounding.
  • Attaching an amplifier to a conducting material.
  • If the power cable has no voltage.

Therefore, select a suitable amplifier wiring kit to ensure your amplifier works smoothly. It is also crucial to check that your amplifier is grounded appropriately, with the ground cable fixed firmly and the connecting area cleaned free of any form of paint.

4. Restarting all the time

A poorly grounded amplifier will keep on switching off randomly.

Loose or incorrect grounding is amongst the most common causes of amplifier failure.

Therefore, make sure that every connection is firm, and no loose cable strands are sitting around that may cause a circuit breaker.

Also, verify that the ground connectivity is right, particular for tightness and security.

Factors that cause a continuous switching on and off of an amplifier are:

  • Poor connection of speakers.
  • Mismatch in impedance.
  • If the internal features have a defect.

5. Whining noise

Different causes might cause a disturbance that can affect the entire automobile sound system. This makes finding the fault very hard and time-consuming.

The two prevalent causes of these disturbances are poor amplifier installation and grounding.

To solve this, ensure that the amplifier is appropriately grounded and its metallic enclosure is insulated from the car’s frame. In addition, you can also use a noise filter or suppressor in some cases. Also, your ground cable should not be greater than eighteen inches long because a lengthier line can cause disturbances.

Furthermore, patch wires, ground cables, antenna wire, or other parts of your audio system can increase unwanted sounds.

The issue is finding out where the noise is originating from in the first place.

6. Burning or fire

The worst sign of poor grounding is fire or burning. This is because it exposes you and your car to danger.

Heat is generated where there is friction. In subject to which a faulty ground, either on the amplifier or where it is mounted to the frame of your car, could melt the amplifier ground connection, generating sparks and eventually fire. Therefore, constantly double-check that it is securely mounted to avoid tragedy.

How to Fix Your Car Amplifier?

If your amplifier was not operating appropriately or when you test it with a multimeter, you find any error you can fix as follows.

1. Gather the appropriate tools

The tools needed to fix your amplifier are:

  • RCA cable.
  • Cooling fan (not a must).

2. Remove the wiring

Next, remove all the cables from your car amplifier but remove the ground, remote, and power cable.

3. Check the connections of the amplifier

The amplifier is supposed to be connected to the ground wire.

The ground wire should be free of any rust and a metallic wire.

Also, check if the remote wire is hooked to the blue wire and connect.

4. Test the connections

Using a multimeter to measure voltage, test the connections.

5. Inspect the amplifier

The connections showing no voltage of the amplifier may be loose or damaged. Therefore you must check the open hardware, screws, and nuts.

6. Reconnect the wires

It would be best if you reconnected the speaker wire and RCA cable. Ensure that the speaker connections are not touching the car else. It will create noise.

7. Check the transistor

Connect the transistor to the multimeter and check if any of them show zero resistance measured in ohms.

If anything is defective, then replace it instantly.

8. Turn down the gain

If your amplifier is heating, it might turn your gain too high.

If that is the situation, I would recommend getting an extra fan to cool down your amplifier whenever it gets hotter.

If you cannot fix the problems, then have a technician look.

Furthermore, it would be best to take some precautions when testing a car’s amplifier with a multimeter.

Precautions:

  • Never use a digital multimeter whose wires are damaged.
  • Always keep test leads and the dial in the proper position to make accurate measurements.
  • Never try to use the resistance when checking the power of your amplifier. It will damage your multimeter.
  • There are finger guards on the test probes. Therefore, for your safety, always put your fingers on the finger guards when testing the amplifier.

Conclusion

In conclusion, when you follow all the above steps correctly, testing an amplifier with a multimeter will be an easy task for you. Also, remember to take precautions for your safety and one of your devices.

Related Posts

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

Steps of Mounting a Subwoofer in Trunk

Easy Steps of Mounting a Subwoofer in Trunk

are car equalizers worth it?

Are Car Equalizers Worth It?

How to Play Music From Phone to Car Without Aux or Bluetooth

How to Play Music From Phone to Car Without Aux or Bluetooth

Ways of Improving Bluetooth Sound Quality In a Car

8 Best Ways to Improve Bluetooth Sound Quality In a Car

How to Tune a Car Amp for Mids and Highs

How to Tune a Car Amp for Mids and Highs

Recent Posts

  • The Best CO-Axial Speakers
  • Types of Car Speaker Connectors and How to Connect them
  • Easy Ways of Testing a Car Amplifier with a Multimeter
  • Top 10 Cheapest Android Auto Head Units
  • Steps to Connect a Subwoofer to your Car Stereo Without an Amp

Site Footer

  • Facebook
  • Instagram
  • Pinterest
  • Twitter

About Us | Contact | Privacy Policy | Affiliate Disclosure | Terms of Use | Cookie Policy | Comment Policy | Sitemap

Copyright © 2023 Audio In Car. All Rights Reserved. No part of this site may be reproduced without our written permission.