Rated 4.9 Stars based on 6,700 reviews
Fast Delivery
Customized Service
HomeTips & GuidesAmp Fuse Blown: What are the causes?

Amp Fuse Blown: What are the causes?

It is normal in the automotive industry to have amp fuses blown. Most of the time, these amplifiers blow for no reason. But if it occurs frequently, it should be a cause for worry. Fortunately, fixing a blown amplifier fuse is not a difficult task. 

This article will discuss how easy it is and the steps to follow when fixing a blown amp fuse. Let’s dive right in!

Table of Contents

Why Does Your Amplifier Keep Blowing up Fuses?

There are many components within a car that makes it functional. An amplifier and a fuse are two of the many.

A fuse is a delicate component in a car.

It is because it only allows a certain amount of current to pass through it.

Any more current past its threshold could damage the fuse.

Apart from excess current, there are other reasons your amp would blow up your fuses.

Below is a brief description of each of the reasons:

An impedance mismatch

An amplifier has specifications to handle a certain power load.

So, if you use speakers that overpower the amp, the amp will have to draw more power from the battery.

By so doing, the amp will overheat, damaging the fuse within.

Therefore, you need to install speakers that are compatible with your amplifier. It will prevent unnecessary damage. 

A wrong power cable gauge

A gauge is a cable’s thickness, and several wires have different thicknesses.

The wire gauge will determine how much current the amp can draw. 

So, when choosing a wire to use with an amplifier, ensure it’s of the correct gauge and length.

An incorrect fitting will overheat, shut down or reduce the amp’s lifespan.

a colored power cables

(colored power cables)

Damaged Power supply

When an amp fuse blows as soon as you switch on the amplifier, there’s a power supply fault.

It is also the case when it blows immediately after you insert the fuse. Such situations will call for immediate amplifier servicing.

Faulty Wiring

A faulty wiring system is a major cause of the amplifier fuse blowing up. It can result from poor wire labeling or an amateur performing the installation. 

Thus, during installation, always be careful when handling the wires.  Any mistake in the wiring can cause damage even to other electrical components. 

Excessive Heat

Excessive heat can also cause the amplifier fuse to blow up. Causes of excess heat around an amplifier are poor ventilation and using too much power on it. For this reason, check your ventilation and cooling system if your amp often blows your fuses. 

Wrong Fuse Size

Fuses come in different sizes depending on how much current they carry. Amplifiers also have a fuse rating specification. 

Now, if you use a small fuse in a system that requires more power, it will blow. Similarly, if you use a bigger fuse size, it will not burn out. Instead, it will fail to protect the amp during a power surge. 

thermal fuses

(thermal fuses)

Speaker Problems

Sometimes, an amplifier blows up fuses when there is an issue with the speaker.

To correct this, physically open up and inspect the speaker. You will find a damaged voice call in the speaker that needs replacement.

Amp Gain

When an amplifier has the wrong amp gain, it will produce a distorted sound.

Sound distortion will cause the amplifier to overheat, eventually blowing up the fuse.

Also, a higher amp gain will make the amplifier draw a lot of current, making the fuse blow. 

Shorted Power Wire Between Amp and Battery

A fuse between the battery and the amplifier won’t protect the area between the fuse holder and the battery.

This unprotected area can come in contact with the other car parts creating a short circuit.

Eventually, causing the fuse to blow. 

Using zip ties through the cable will help prevent this occurrence from happening in the future.

Faulty Amp

You should consider changing your amplifier if you can’t fix your fuse problem.

It is because some components in the amp could be damaged. And replacing the entire amp could be the cheaper option. 

car amplifiers

(car amplifiers)

How to Repair an Amp That Blows up Fuses?

Before you do any repairs on an amp, you have to:

Amp Fuse Blown: Check the wiring and fuse values.

A proper fuse value should be at least 10% of the system’s current draw.  It will ensure your sound system is operating correctly.

Additionally, the fuse rating should match the amp rating and cable rating.

The cable you use should supply enough power to the amp without overheating.

Amp Fuse Blown: Check for chafed cables.

Chafed cables are a result of poor installation. Naked wires pose a car hazard since a vehicle’s chassis offers little to no electrical resistance.

Most times, when a naked wire comes into contact with a conductor material, it will draw power from it. 

This power will combine with the one drawn from the batteries making it excess.

The fuse will not be able to handle this kind of power, making it blow. 

cable crimpers.

(cable crimpers.)

Reduce amp gain

It is common for people to confuse an amp gain and an increase in the volume.

At the same time, a volume increase cannot damage the amplifier, an amp gain will. 

The extra gain will overwhelm the system, especially the amplifier, resulting in a blown fuse.

To reduce the gain, set it to optimal levels.

Next, you can increase the amp until you hear some sound distortion.

Once you get the distortion, reduce the amp until the distortion disappears.  

Check ground connectors

Ground connections should be within 18” of the am for proper functionality.

Also, the quality of the connection should be top-tier. To ensure this, always use a crimp to cut wires.  

Poor connections commonly lead to damaged amps and fuses.

Always secure every cable before activating your system.

Check for internal defects in the amp.

If all else proves futile, this should be the focus of action.

Your amplifier may have some damaged components.

You can replace it with a new one.

a vintage stereo amplifier

 (a vintage stereo amplifier)

Operation steps

  • Step 1: Unplug the amplifier from the power

Unplugging any electronic item from the main power supply before the repair is always a safe practice. If necessary, you should also turn off any internal switches. Ensure that no power is flowing through the amplifier.

  • Step 2: Remove Cover

Use a Phillips screwdriver to remove the screws from the case of the amplifier.

Pull up the case to reveal the amplifier. Remove the amp from its secured place and lay it down in a clear workspace.

  • Step 3: Find the blown fuse

A fuse should have a holder. Some of these holders are glass-tube type, while others are blade-tube type.

Whichever type, a blown fuse should have a black spot on it. Remove the fuse and replace it.

  • Step 4: Determine the type of fuse to replace it with

To know the exact rating of the fuse, look inside the amp. You’ll find the manufacturer’s name and model number in there. 

Research this information and get its replacement from an authorized service provider. 

a blown fuse

(a blown fuse)

Frequently Asked Questions.

  • Will an amp turn on with a blown fuse?

An amp cannot function with a damaged fuse. A blown fuse would create an open circuit cutting off the current flow. 

  • Can a 15-amp fusee be replaced with a 20-amp fuse?

You can use a 20-amp fuse in place of a 15-amp. However, this practice is not advisable. It is because the current flowing through the 20-amp would be higher and could cause damage.

  • Do fuses affect sound quality?

A fuse has no hand in the quality of sound your speaker produces. 

modern car speakers

(modern car speakers)


Amplifiers are key components in any speaker device. Following the steps in this guide would effectively fix your amplifier.

Consult a professional if you follow these steps and can’t solve your problem.

We hope our article helped you learn about blown amp fuses.

Hi I am Christa, sales manager of Cloom.

I have extensive expertise and experience in wiring harnesses and I believe I can help you.

And we have a very professional technical team who can clearly understand the customer’s needs and give professional suggestions and solutions after receiving the drawings.

If you also have wiring harness needs, please send me the drawing so that we can give you our quote and start our business.

Background media

For Better Future
and Business
Let’s Talk Now!

Fill in your details and we’ll get back to you in 24 Hours.

Contact Form Demo


[email protected]




3rd Floor, Nanhai Plaza, NO.505 Xinhua Road Xinhua District,
Shijiazhuang, Hebei, China. 050057


© 2007- 2023 Cloom tech. ALL RIGHTS RESERVED.



Subscribe to our newsletter for the latest updates, exclusive offers, and exciting news delivered straight to your inbox.