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Why Does Car Amp Fuse Keep Blowing?

If your car amp fuse keeps blowing, it can be frustrating and costly.

You may not know what’s causing the fuse to blow, making it difficult to fix. So, what are the reasons for car amp fuses to blow, and what can be done to prevent it? Let’s find out.

Car amp fuses keep blowing for one of three reasons:

#1. The amplifier is drawing too much power from the battery.

#2. There is a short circuit somewhere in the amp.

#3. The amplifier is overheating.

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

Tip: For any inline fuse, use a dedicated fuse box. This will help the fuse from any damage and also the connection from the moisture or dust.

There are many fuse holder types and variations, but I use InstallGear for the blade fuses and have found Stinger to be the best for glass fuses (links to Amazon).

In this post, I’ll explore some common causes of blown car amp fuses and provide tips on how to stop this from happening in the future.

Why Do Car Amplifiers Blow Fuses?

In most cases, an amplifier will blow fuses due to internal damage caused by the way it was installed, meaning that the components pull too much current from the power supply.

When this happens, the only way to protect the amplifier is to install an inline that will blow in the overload conditions.

Many times, an amplifier won’t show signs of improper installation until it’s too late, and blowing fuses indicates that damage has been done. The common overlook during the wiring is the bad amp’s grounding.

If the ground wire is not connected correctly to a clean, unpainted metal surface, it can cause all sorts of problems, including blowing fuses.

Another reason an amplifier blows fuses is if the power and ground wires are too close together.

When they’re close together, they can create a so-called “ground loop”, which will cause the amplifier to overheat and eventually blow a fuse.

This is especially notable when the power wires are too thin (too large AWG) with bad shielding.

The rule of thumb is to keep the power and ground wires as far apart as possible.

How to Check if Your Car Amp Fuse Is Blown?

The simplest way to check if the car amp fuse has blown is to check visually if the thin wire inside is melted. If it is, it’s a good indication that the fuse is blown and needs to be replaced.

To check the fuse visually, you have to:

#1. remove the fuse from the fuse holder

#2. hold it up to a light

#3. check if the wire inside is melted

Before opening the fuse holder, check if it is not too hot, as this can indicate a bigger problem.

If you do not see that a fuse may be blown but still think it might cause the problem, you can use a multimeter (link to Amazon) to check if it’s functioning correctly. To do this:

#1. disconnect the amplifier from the power supply

#2. set the multimeter to continuity mode

#3. connect one lead of the multimeter to one end of the fuse

#4. connect the other lead of the multimeter to the other end of the fuse

If the multimeter beeps, it means that the fuse is not blown. However, if there’s no continuity, the fuse is most likely blown and needs to be replaced.

What to Do if Your Car Amp Is Blowing Fuses?

If your amplifier is blowing fuses, the first thing you should do is check the installation.

Make sure that all the wires are correctly connected and that no loose connections or any suspicious places are causing a short circuit.

Next, check the power and ground wires to see if they’re too close. If they are, try to move them apart. If the problem persists, you may need to replace the wires with larger ones.

Finally, check the fuse itself. If it’s blown, replace it with a new one of the same rating.

When you notice the amplifier is still blowing fuses, there may be something wrong with the amp itself. In this case, it’s best to take it to a professional for diagnosis and repair.

If your amplifier is drawing too much from the battery, it’s probably because the speakers demand too much power, often due to lower amplifier impedance.

This can happen if you’re using too many speakers per channel or if your speakers are mismatched (i.e. one is rated for 100 watts, and the other is only rated for 50 watts and connected in parallel).

If there’s a short circuit somewhere in your amp, that’s probably causing the fuse to blow. To find and fix the short, you’ll need to open up the amp and investigate inside.

Checking the internal electronics in the amplifier, all transistors and connections can be tricky, so it’s best to take it to a professional if you’re not confident in your abilities.

If your amplifier is overheating, that’s usually because it’s not getting enough ventilation.

Ensure the amp is mounted in a well-ventilated spot and that nothing is blocking the airflow around it. If the problem persists, you may need an amplifier with larger cooling fans.

How to Prevent Car Amplifier From Blowing Fuses?

There are a few things you can do to prevent your amplifier from blowing fuses:

#1. Make sure the power and ground wires are of the correct size and properly connected.

#2. Keep the power and ground wires as far apart as possible.

#3. Use high-quality, thicker gauge wire for the power and ground connections.

#4. Make sure the amplifier is adequately ventilated.

#5. Use a higher quality fuse placed in the temperature and water-resistant fuse box.

If you follow these tips, you’ll be much less likely to blow a fuse in your car amplifier. However, if it does happen, now you know how to check and replace the fuse.

The Symptoms of a Blown Car Amp Fuse.

If your car amplifier fuse has blown, you will notice a loss of the music as the amplifier stops working. In most cases, the sound is completely cut out, but if you have more than one amplifier, some speakers may still work.

If you suspect that the fuse has blown, the first thing you should do is check it with a multimeter. If there is no continuity, then the fuse needs to be replaced.

Once you’ve replaced the fuse, if the amplifier still isn’t working correctly, there may be another problem that needs to be taken care of.

In this case, you may need to reset the amplifier, but if it still does not work correctly after checking the installation, it’s best to take it to a professional for diagnosis and repair.

Can a Blown Car Amp Fuse Be Dangerous?

A blown car amp fuse is not dangerous, but this indicates something wrong is happening in the car audio installation.

If the fuse blows repeatedly, there may be a short circuit somewhere in the system, and this can be dangerous as it may cause a fire.

It is crucial to find and fix the problem as soon as possible to avoid any further damage. If you’re not confident in your abilities, you should take it to a professional for a detailed investigation.

How to Replace a Blown Car Amp Fuse?

If your car amplifier fuse has blown, you will need to replace it with a new one. To do this, you’ll need a few tools:

– A screwdriver

– A multimeter

– A replacement fuse of the same rating as the original one

#1. Use the screwdriver to remove the fuse from the holder. Then, use the multimeter (link to Amazon) to check the continuity between the two leads on the fuse. If there is no continuity, then the fuse needs to be replaced.

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#2. Take the replacement fuse and insert it into the fuse holder in the same orientation as the original fuse. Once it’s in place, screw the holder back on.

#3. Now, turn on the car amplifier and test it to see if it’s working correctly. If not, there may be another problem that needs to be addressed.

After replacing the fuse, remember to put all rubber seals back in the fuse block so that moisture and dirt will not enter and cause problems.

The Best Way to Avoid Blowing Car Amp Fuse

The best way to avoid blowing a car amplifier fuse is by following these tips:

#1. Make sure the power and ground wires are of the correct size and properly connected.

#2. Keep the power and ground wires as far apart from each other as possible.

#3. Use high-quality, thicker gauge wire for the power and ground connections.

#4. Make sure the amplifier is adequately ventilated.

#5. Use a higher quality fuse placed in the temperature and water-resistant fuse box.

Common Mistakes That Can Cause a Car Amp Fuse to Blow

There are several installation mistakes that can cause an amplifier to blow fuses:

#1. Installing the amplifier near sources of heat:

If your amp is installed near the engine or in a hot and humid environment, the excessive heat can damage the internal components and cause the fuse to blow.

#2. Incorrectly wiring the amplifier:

If the amplifier is not wired correctly, it can cause a short circuit that will blow a fuse. Consult the manufacturer’s instructions or have a professional do the installation to avoid this mistake.

#3. Not using an external capacitor:

A capacitor helps to stabilize the voltage coming from the car’s electrical system and prevents spikes that can damage the amplifier. If you don’t use a capacitor, your amplifier is more likely to blow its fuse.

#4. Using a fuse of the wrong amperage:

If you use a fuse that is too small for your amplifier, it will blow more easily. Be sure to use the correct size fuse as specified by the manufacturer.

Conclusion

If your car amp fuse keeps blowing, it can be frustrating and costly. In addition, you may not know what’s causing the fuse to blow, making it difficult to fix.

However, by understanding some of the common reasons for blown car amp fuses, you can take steps to prevent this from happening in the future.