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Signs of a Bad Car Amplifier

The amplifier is an integral part of any car audio system.

New car audio enthusiasts try to go cheap on their amps and buy a b-grade unit from Ali Express. These amps tend to overheat, produce weaker bass, and worsen the car music experience.

But even if you choose a reputable brand, the performance level of the amp will start to degrade after a few years. At that point, you have to be alert and replace it before it causes any damage to your speakers/subs.

6 Signs of a Bad Car Amplifier

Below are the six signs that indicate that an amp is dying or has already died.

1. Amp frequently Blowing Fuse

The fuse is a safety device installed in amps to prevent it from damage during a power surge. Whenever there’s a huge amount of current flow, the fuse melts apart and protects the amp – by opening up the circuit.

If your amplifier is frequently blowing fuses, then there’s a possibility of an internal problem.

But you shouldn’t be quick in reaching any conclusion the amplifier can also occasionally blow fuse if there’s poor grounding, load mismatch between amp and speakers, or incorrect amp gain.

2. Amp Going Into Protect Mode

Similar to the fuse, there’s the protect mode.

It’s a safety mechanism that puts the amp into a shutdown state to prevent further damage. It’s usually activated due to amp overheating, improper installation, loose/faulty RCA cables, short-circuit, etc. And you can bypass this mode by solving these issues.

But if you have none of them and the amp is repeatedly going to the protect mode, it indicates an internal fault in your amp.

3. Amp Overheating for No Reason

The third sign you should look for is the amp temperature.

As they get a lot of power from the battery, it’s natural for the amps to generate some heat. But if it’s overheating (too hot to touch with bare hands) even with AC on, there’s something wrong.

Usually, it’s the load mismatch, incorrect amp gain, or a poorly-built amplifier. You can try to prevent the overheating by solving these problems, providing proper airflow, or maybe getting a fan for the amp. But if there’s no improvement even after implementing all of this, it is a sign that the amp is slowly going towards an internal failure.

4. Amp Not Turning On at All

Under normal circumstances, you’ll need to connect ground wire, power, and remote wires to turn on the amp.

You can think of a remote wire as a trigger. Whenever you turn on your car radio, it sends a turn-on signal to the amplifier via the remote wire.

Similarly, you’ll need a power wire for the amp to get the power from the battery. If these wires are damaged/corroded, loose, or shorted out, the amplifier will not simply turn on.

And if all of these wires are good and fuses are in place, but the amp is still not turning on, it’s probably has breathed its last. And you should replace it as soon as possible.

5. Inconsistent/Weaker Output

If your subwoofer is cutting out at higher volume or not producing as much bass as it used to, it can be due to a bad amplifier. But like other issues, there can also be other reasons, such as poor-quality wiring or an average-quality subwoofer. The speakers producing crackling sounds, especially at higher volumes, also fall into this category .

Therefore, you should consider these possibilities too.

6. Burning Smell Inside Car

The last indicator of a dying car amplifier is the burning smell inside your vehicle. Typically, this smell is due to two (or more) internal parts of a vehicle component colliding against each other (and creating a friction). The common causes behind such smells are older clutch, brakes, electrical short, oil leakage, and faulty amp.

Since these issues vary greatly in nature, it’s better to consult a mechanic and let ’em diagnose the actual reason behind this smell.

Michael Brown is the founder of, a website that provides car audio installation guides and tips. A self-taught car audio enthusiast, Michael has been installing and modifying car stereo systems for over 15 years.

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