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Why My Car Amplifier Has Stopped Working?

There are several reasons why your car amplifier doesn’t work. Is it making hissing sounds? Do you hear clipping sounds? Or the car amp doesn’t power on at all.

Whatever the diagnosis, if your car amplifier has stopped working, more than often, it’s because of an operator error.

Generally, car amplifiers stop working mainly due to wrong wiring or incorrect amplifier setup. For example, an internal fuse may be blown or a connection cord damaged. Also, the ground and power cables may not transfer enough voltage to meet the amplifier’s electrical current needs, causing it to overheat and turn off, or the amplifier may be incorrectly grounded.

As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.

Tip: When installing an amplifier, choosing the best wires is vital to not compromise the quality of the whole system, and when selecting wires for the amplifier, try to aim for the OFC wires. They may be slightly more expensive than typical CCA but offer higher signal transfer quality at the same gauge size.

I use Knukoncptz wires and can recommend them to anyone looking for the highest quality products.

In the article below, I will go through the most common reasons for the car amplifiers to stop working and show you how to avoid this from happening in the future.

Common Problems That Cause My Car Amplifiers to Stop Working 

Why isn’t your car amplifier not working? Well, whenever your car amp fails to work, it rarely has something to do with the amplifier itself.

The problem is due mainly to the connection between the amp and the speaker. Luckily, it’s easy solving common causes for a faulty car amplifier. 

Here are a few diagnoses if your car amplifier doesn’t work.

Clipped Sound Signal

Clipping is attributed to poor or inadequate grounding. This problem arises when the car amplifier must generate more power than it can, creating dissonance.

When the amplifier is pushed past its capability to produce enough power to replicate the input signals to speakers, the initial sound of the input signal will be degraded.

In as much as the signal will still be amplified, but it will be in a skewed and distorted form. As a result, the music quality will not be the same, and over time, this can also damage your speakers. 

Clipping can also be caused by overheating, too-high input sensitivity, insufficient wire gauge, and over equalizing the source signal. 

Restarting at Random

There is nothing more annoying than your amplifier switching on and off at random. Unfortunately, this is another failure as a result of poor grounding.

You need to ensure every connection is tight because loose cable strands can produce a circuit breaker.

Other causes for this are the speakers’ inability to connect correctly, a mismatch in impedance, defective internal components, or overheating. 

Fire (or Burning)

Burning is perhaps one of the worst problems you can experience with your amplifier because it not only poses a danger to your car but to yourself too.

This is the extreme result of poor grounding, often caused by overheated and melting wires.

Faulty grounding and poor connections to the frame of your car will melt the amp ground connection causing friction. Friction produces heat, generating sparks that can evolve into a fire.

I cannot emphasize enough how important it is to ensure your amplifier is grounded correctly and securely fastened to avoid this worst-case scenario. 

The Amplifier Turns On, But No sound.

Your amplifier can be working, yet you fail to get any sound. This is because the ground wire is not getting a solid signal. The car battery may also be down, and the amplifier is not getting enough voltage from it.

When the power cable becomes faulty or unhooked, you will not get any sound, or the RCA cords are unplugged or destroyed.

Your speakers can also be why you are not getting any sound. So after testing your amplifier, it is worth checking on your speakers. 

Hissing or Other Sound Distortions

When you start hearing weird sounds coming from your amplifier, it can be because the head unit cables are running some interference with the ground cables. This causes some distortion in the sound.

Speaker wires can also cause sound distortions when they touch each other. In some cases, you need to reroute the wires to avoid getting close to the ground or power cables.

Go for cable with good quality and wires with good shielding to prevent reoccurring.

When the subwoofer is overpowered or underpowered, you will experience some sounds like farting. This can be a little unpleasant, especially when you have company.

Ensure that the enclosure on your subwoofer is the right fit. For example, mount the speakers well to avoid air from escaping while listening to music, resulting in fart-like sounds.

If you have a ported enclosure, do not block the port because there must be free airflow from the subwoofer.

How to Repair Car Amplifier?

When your amplifier starts experiencing problems, the first fix-it tip is to use a multimeter or continuity tester.

The continuity tester helps check the continuity of audio cords that come in and go out of the amplifier.

First, disconnect all other audio sources from the amplifier. Now test only the internal speakers to see if the unit receives enough power or produces good sound.

If all these are in good shape, the problem is inside the amplifier. At this point, you will have to disassemble the amplifier to fix the internal parts.

Step 1

Unplug the electrical cord from the wall receptacle. This is to avoid any shock while handling the amplifier. 

Step 2

Separate the cover from the chassis by removing all the screws side, back, and bottom. 

Step 3

Separate the two halves and expose the internal components on the chassis or lower frame of the amplifier.

Step 4

Check if the electrical cord’s internal end is loose or damaged due to constant pulling. If the internal elements are loose, tighten them and if damaged, replace them as needed.

In this case, it may be worth sending the amplifier to the electronic service because any mistake during internal amplifier repair can cause its permanent damage.

Step 5 

If the cord works, inspect the internal fuse. Test the fuse if it still works and if it is blown, replace it. 

Step 6

Clean the inside of the amplifier. Most of the time, you experience problems with your amplifier because it is dirty inside, full of dust, which may cause its internal parts to overheat.

Blow away dust using a can of compressed air or a hairdryer. If the unit contains too much dust and dirt, use a vacuum cleaner with a plastic tip.

The plastic tip protects the delicate parts of the unit from receiving static electricity.

Step 7

Clean the input jacks and speaker terminals using an electrical contact cleaner. Check if any input jacks have been disconnected from the wires and reconnect them.

If you follow all these steps and nothing changes, be sure to seek professional help. 

How To Properly Ground Your Car Amplifier?

Most of the amplifier problems we have seen result from poor grounding. It is safe to say that properly grounding your amplifier can eliminate 90% of your amplifier problems.

Here is how to ensure your amplifier is properly grounded. 

Find the Best Ground Location

Finding a good ground point is very important. The location should be within 18 inches of the amplifier.

Attach the power wire with a screw directly to the bare metal chassis for a better connection. Check for easy ground screws and if there is none, drill into the car’s chassis. 

Cut the Ground Wire

Cut the ground wire and ensure it is a thick one. Thick wires have the capacity to better accommodate high amperages needed for car audio systems. Thin wires can lead to overeating and burning of the amplifier.

Attach the Wire

After cutting the wire, you will need to reattach it to the receiver. Strip the wire before attaching it to the receiver.

You will notice a ground connector point at the back of your amplifier. Connect the wire to this port and ensure it is very tight. 

Tighten the Grounded Ports

Loose wires can result in faulty grounding. Once the wires have been attached, ensure they are tightly tightened around the amplifier. 

You can even use tape to ensure they hold their position. 

Do a Test Run

You can never know I the grounding was successful until you do a test run. Turn the car stereo on, and test the receiver.

Use a digital multimeter and a lead extension to conduct this test, a properly grounded amplifier should give you reading at around 0.5 ohms.

How Do Speakers Damage Your Car Amplifier?

The speaker can damage an amplifier through an impedance mismatch. This happens when the amplifier impedance is higher than the speaker’s impedance.

In other words, the speaker draws more power than the amplifier can produce, which results in overheating and damage to the amplifier.

To solve this problem, buy a speaker that matches your amplifier capabilities and connect the speaker wires carefully, but actually for a new car audio system, you should buy the amplifier that matches the speakers.

How Do I Identify My Car Amplifier Problem?

It is important to watch out for the signs that your amplifier could be having a problem. The longer the problem goes without fixing, the worse the damage becomes.

  • The first sign to identify an amplifier problem is when it produces no sound. This is after you have made the proper connections. If there is still no sound, it means the amplifier is damaged.
  • The second sign is a distortion in the sound of the amplifier. So when you start hearing your amplifier making strange noises, it is safe to assume there is something wrong with it.

Distortion occurs when the speaker’s power demand is much greater than the power the amplifier can supply. As a result, the sound will be distorted when the amplifier is unable to meet the speaker’s demands. 

What Do I Need for My Car Amplifier Repair?

Like all other appliances, opening up an amplifier will require specific tools. For example, you may need to open up your amplifier to clean the inside, replace a fuse or fix an electrical cord.

For this, you will need:

  • Philips’s screwdrivers
  • An electrical contact cleaner spray with a can of compressed air if you decide to clean.
  • Soldering iron.

What’s the Protect Mode Feature in My Car Amplifier?

Many new model car amplifiers come equipped with the protected mode feature. This is a built-in safety feature that is meant to protect your amplifier.

The feature automatically shuts down your amplifier when it starts experiencing problems to prevent further damage to the unit.

Once the amplifier goes into protect mode, you may not use it until you fix the problem. Others can turn back on but go back to protect mode if the problem is not fixed.

Why Is My Car Amplifier’s Protect Mode On?

The amplifier can activate the protect mode feature because of several reasons.

  • For starters, the Protect Mode turns on when there’s an internal error. 
  • Secondly, the amp’s wires may be loose or faulty, which usually causes interference in the unit.
  • Thirdly, the Protect Mode comes on if the amp isn’t correctly installed or when it is poorly grounded.
  • Lastly, check if the unit is overheating.

With a turned-on protect mode, it’s a notification that you should inspect your amplifier’s speaker, cables, subwoofer, and other components. 

The protect light mode will turn off once you’ve fixed the problem.

Related Questions

Here are frequently asked questions regarding a car amplifier that doesn’t work. 

What Does it Mean When My Car Amplifier Powers on But There’s No Sound?

This happens when your amplifier is not getting enough voltage, which in the case of passenger trucks or light trucks is a 12V that is needed to turn on the amplifier and get sound.

If the voltage is less than 12v, it may not turn on sound. Check your AMP TURN ON signal and choose the 12v on the head unit wire harness.

Why Is My Alternator Whining?

Insufficient grounding can cause your alternator to start whining, especially when the car engine is turned on. The bad grounding is either your speaker’s amplifier or the head unit.

Find a better location to ground your amplifier, such as the body or frame of your car.

Additionally, if you are experiencing headlight dimming when your amplifier is turned on, then it means the stereo is using too much power for the alternator to keep up.

You can cure this by wiring in a capacitor that will help curve the spikes in power and ensure the amplifier is constantly only using 12V.

If this does not help, upgrade your alternator, OEM alternators don’t generate as much power – upgrade to one that can handle your amplifier. Or better yet, get a better battery.

How Do I Know My Car Amplifier Is Poorly Grounded?

If your car amplifier is not grounded correctly, you will notice some signs such as overheating, clipped sound signals, randomly turning on and off, or worse, burning.