12 Signs Of A Bad Car Amplifier & 9 Common Causes

Broken amplifiers may ruin your enjoyment when driving. So how to tell if they are working badly and need replacement? The clearest symptoms are the heat, burning smell, and poor sound quality from your stereo. You may also notice that the amps can’t work normally. We will discuss some factors telling that your car amplifier is in bad condition and recommend solutions accordingly. Let’s join us and learn how to treat your car stereo properly!

Signs Of A Bad Car Amplifier

There are a few indicators to look for when determining whether or not your automobile amp is faulty.

We’ll go through every point, so you know what terrible amp symptoms are.

The amp doesn’t turn on.

Your amp not turning on is the first sign. The cause for this problem may be a broken amp, a loosened wire, or a blown fuse.

In this case, examine the blown fuse first because it is the most frequent issue for the amp.

Next, make sure that you have connected the wires securely and properly. Once a connection is loose, it will affect the whole system.

Besides, check to plug the amp into the outlet correctly, and that your automobile is running with power.

If everything seems fine, but you can’t get the amp to work, it may have gone bad and needs replacement.

Device not working is one of the signs of a bad car amplifier

Poor sound quality

If the sound in your automobile has worsened over time, it might be a symptom that it is defective.

We recommend reviewing the blown speaker symptoms and examining the wiring that links the amps to other components of your audio system.

The problem may arise due to the worn-out wire or a blown speaker. Checking all the components helps you detect the cause.

Excessive bass

If the bass from your stereo is too loud or you notice excessive sound distortion, the audio system is not working normally.

Such issues might occur when the amplifier does not have enough electricity to operate all of your subwoofers and speakers.

If you feel so annoyed with too much distortion and bass, it’s time to buy a new amplifier to enhance your experience.

You have a terrible listening experience

The protection mode is always active.

If your amp is always in protect mode, it is undoubtedly breaking down and needs you to treat it as soon as possible.

Amplifiers activate the protection mode to protect themselves from getting damaged. If you see this mode running too often, your device must not be working correctly, and its internal components may malfunction.

However, you should check all external factors for the activated protection mode so that you don’t mistake a small wire or connection issue for a serious problem like a broken device.

No output

An absence of output from your amplifier might suggest that it is defective and needs replacing.

If you’re having difficulties with this symptom, first troubleshoot the issue before assuming that your amplifier has broken.

Make sure that all of the wiring and connections are in proper working order. A disconnected wire may prevent the amplifier from delivering any sound.

If you’ve double-checked all of the cables and connections and still don’t hear anything, your device must be faulty.

There is no output

Slap and pop sound

If your subwoofers are making a loud pop or slap sound, it might be an indication that your amplifier is malfunctioning.

You can solve this problem by replacing the power supply. If the pop and slap sound still persists, replace your amp.

Blowing fuses

Car fuse blowing is a regular problem that people encounter daily. Blowing fuses in huge numbers is not rare, and it may not be very pleasant for some drivers.

If you constantly need to change the amplifier’s fuses, it’s a clue that something is incorrect, and it needs some checkups.

Fuses can safeguard the amp from damage. If they continue to blow, the problem may become more serious.

When you encounter this symptom, take your automobile to a specialist to get it examined and serviced.

Before contacting a specialist, you can check the connectors, power wire, output and input cables, and jacks to detect any wear and tear. Torn cables might weaken the system and cause the fuses to blow constantly.

It’s also possible that the fuse is blowing because it’s the wrong size. So, before taking the unit to the store, figure out what kind of fuse your vehicle needs.

You may measure the fuses you require using the size chart for blowing fuses.

Here are three types of fuses:

  • ATC

You can see ATC fuses in commercial vehicles such as school buses or semi-trucks. They protect the system against stressed circuits with too much electricity.

Whenever the fuses detect excessive voltages, they will immediately interrupt the circuit system.

  • ATO

ATO fuses do not really blow until they become overloaded or short-circuited for a long time.

  • ATCO

ATCO fuses have an integrated resistor that helps them stay on before shutting power off.

There are many things to do with the fuses


Car amplifier overheating is one of the clearest symptoms that your automobile amplifier is dying. A fault with its cooling system is generally to blame.

Most of the time, only the cooling fan has stopped functioning. However, in other circumstances, the amp may get too hot that the fan is unable to maintain the temperature within a safe limit, leading to a breakdown.

To avoid such problems, make sure there’s enough space around the amplifier for the fan to blow away the hot air and for the equipment to breathe.

Furthermore, do not overburden the system since things can easily go bad if the stress is beyond their limits.

Inconsistent audio output

Poor car amplifiers can also cause inconsistent audio output, delivering high loudness or low volume.

This symptom usually occurs in conjunction with other problems with broken car speakers, head systems, or subwoofers.

Yet, the most typical explanation is that something is wrong with the amplifier.

If you’re experiencing this symptom and have eliminated all other possibilities, the car amp may have collapsed, and you’ll need to either repair it or replace it.

The output is not stable

Amp randomly restarting

The common cause of an amplifier restarting randomly is a fault with the wiring.

You can blame the connector or the fuse, but mostly it’s the car amp itself that causes trouble.

So first, check the external elements such as connector and wire issues, power fluctuations, and the broken stereo. If they seem fine, it’s the amp to fix.

Burning smell

You can quickly notice the burning smell. A fault with the amp’s cooling system or power supply is often the source of this odor.

When the cooling system breaks down, or the power source gets too hot, the insulation that shields the circuits from moisture begins to burn.

If you see black smoke rising from beneath your hood, it might also indicate that something is incorrect with your amplifier.

This indicator suggests that the unit has overheated due to a lack of air and needs treatment.

So, if you have this odor, it’s advisable to take your vehicle to a specialist to get it serviced.

Amp can’t handle the normal load.

If the amplifier malfunctions at the same power it used to take, it is a strong indication that the system seems to be either too old to operate or that there is an internal issue.

In all cases, replacing the damaged unit with a new one is the best option for getting things back in order.

Causes Of The Broken Car Amplifier

Temperature extremes, too much pressure, and overuse are just a few of the reasons why the sound system stops working properly.

Temperature changes

Temperature extremes, too much pressure, and overuse are just a few reasons why the sound system stops working properly.

Extreme temperatures induce the electronics to overheat or freeze, making car amps break down.

Consider how you store the amp in your car. You may have tuned it to work within a specific temperature range, which is usually the same as your car’s.

If you’re having trouble with low or high temperatures and haven’t seen any changes in cold or heat levels, your vehicle sound system should be the one to blame.


Abuse is among the most common causes of a car speaker malfunctioning.

It may occur when someone shakes and hits the device or puts something on it. This unit can’t hold too much pressure.

If you see scratches, dents, or even burns on the device, you have abused it and need to change your habits.


Overheating is a common problem arising from the lack of ventilation or faulty cooling system and power supply.

Although most car amplifiers feature built-in protective circuits to avoid harm if they overheat, it does not eliminate the possibility that the heat will lead to further issues.

Your unit may get overheated for some other reasons, such as:

  • Unprofessional grounding

Make sure that your amp connects correctly to the car’s battery via ground wire.

If you’re unsure, ask a professional or reference your car’s owner’s handbook for instructions on attaching it.

  • Lack of ground wires or power

You may overlook ground cables in your setup or forget to purchase a power conditioner.

The conditioner can lower electromagnetic pollution and block out interference from adjacent electronic equipment such as microwaves, televisions, computers, and other similar items.

This conditioner will also shield the amp’s internal parts from voltage spikes and allow it to stay cooler.

  • Closed ventilation

If your amplifier’s vents get blocked with dust or debris, use a vacuum cleaner to clear them out.

A can of pressurized gas will suffice in a rush, but be cautious not to pump it too close to the circuitry. It might pull any tiny particles into the circuit board.

  • Poor build quality

When buying a vehicle amplifier, ensure that it is of high quality. Cheap parts come in low-cost amplifiers. They can’t last long and will ultimately fail.

Before you get one, double-check the warranty if something goes wrong while your device is still under warranty.

Overheating is quite common


Different temperatures place stress on amplifiers. Overstress may also come from overclocking while playing the music.

You’ve probably seen such an issue if you’ve turned up the volume on your automobile audio system — the amplifiers start to crack and pop as they become overwhelmed.

A similar situation can happen to amplifiers if they produce too many watts for their circuits to handle.

Amps can defend themselves in these situations by stopping their tasks until things become more controlled.

Avoid stresses on your device

Power supply

The power supply is in charge of providing sufficient electricity for the system to function. If it fails, the amplifier’s chance of breaking it increases by several hundred percent.

How To Test An Amp?

Testing amplifiers is the simplest way to determine if they are working correctly or not. You should perform the test regularly and adjust your device if necessary.

Clamp test

A clamping test may also help you estimate the raw power (RMS) going out of amplifiers.

Here’s how you can do it:

  • Attach the multimeter’s leads to the speaker outputs.
  • Attach the red lead to the positive terminal and the black one to the negative terminal.
  • You have to connect your speakers to the amp for this method since the clamp meter will need the positive output of the speaker.
  • Switch on the amplifier.
  • Make a trial tone (40Hz will work).
  • Take note of the meter values.
  • Multiply the volts to the amps, and you will know the wattage.

Please remember that changing the gain on the amplifier can essentially affect the readings, giving you a higher value if you set the gain up and a lower value if you turn it down.


You may need to test numerous parts of the amp once you notice some problems with it.

Modern amplifiers now include a large number of fuses as part of the circuit. If the wrong signal travels via these fuses, they will blow.

All you have to do now is double-check that all fuses are still functional. If there is any blown one, you should simply have to replace it.

To test the unit with a multimeter, please follow these steps:

  • Turn off the amplifier and remove its case.
  • Unscrew the circuit board from the casing.
  • Adjust the multimeter’s impedance setting to one with an audible alarm.
  • Evaluate different components of the unit using the elimination method.
  • You’ll need to attach the multimeter’s leads to the accepting input section and the device that will get the output.
  • Flip the circuit board over to reach the soldering spots if you can’t find a component.
  • Test for a circuit at each component with the multimeter adjusted to an impedance range with an audible alert.
  • If the audible alert rings, the component is functioning properly.
  • If the alarm doesn’t go off, you may reasonably assume that the component has blown or broken.
A multimeter is excellent for testing your device


We have talked about the signs and causes of bad amplifiers. The following questions and answers will give you more information about this topic.

What happens when you don’t ground the car stereo?

Without a correct ground wire that is put in your car’s dashboard, you won’t be able to run a car stereo.

When your car and stereo system are not working, the ground wire will enable the stereo to function correctly and without any difficulties.

If your car doesn’t have a ground wire or the ground wire has one loose connection, signal interference will mess with the music you’re listening to while driving.

You can learn some grounding tips right here:

2. What are blown amp signs?

There might be a plethora of symptoms that quickly come out as soon as you turn on the audio system, such as:

  • You can’t hear any sound from the radio although you have already switched it on.
  • There is a notable sound distortion.
  • The stereo system would start producing weird sounds, such as farting.

Why is my amp not putting out sound?

All the possible causes for this problem include:

  • Your speaker has completely blown.
  • The output transformer is either leaky or defective in some way.
  • You were the speaker jack incorrectly.
  • The speaker wire has corroded, or the jacks have oxidized to the point of no longer being able to make a secure connection.


A poor car amplifier’s symptoms aren’t always clear, but you can find them by checking the sound and the device’s behaviors.

If you have any concerns regarding your vehicle’s efficiency or if it has just become damaged, get help from a professional and have your device checked.

Hopefully, you will find this article helpful. If you need any further information, please feel free to ask. Thank you for reading!

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