Smoke Coming Out Of Car Stereo: Do’s & Don’t

What to Do When Car Stereo Is Smoking

Smoke coming out from any part of your car is definitely an alarming scenario. It gets even more alarming when it’s coming out from your beloved stereo system.

Because… then you know that no major damage is going to happen to your car and you’ll be safe, but the stereo system that you built bit by bit is going to become unsuitable for use.

Here I’ll tell you how to check exactly what’s going on in your car’s stereo system when it starts emitting smoke, how to stop the smoke, and how to prevent it from happening in the future. So, without further ado, let’s hop in.


Emergency Response

Emergency Response to Car Stereo Smoking

It’s a fire emergency, so the first and foremost thing you should do before even considering anything else is turn off the car stereo immediately. This would stop the source of the smoke from burning and causing any further damage to your system.

The source of smoke is almost always fire (unless it’s a chemical reaction). Hence, the first thing you should do is try to put the fire out at the source of the smoke.

The safest and most effective way of doing this is by using a fire extinguisher. Warning: Never use water to put fires out in electrical systems.

Several brands make fire extinguishers for cars. These come in small cans and are easy to carry. It’s wise to have a bracket installed in your car for carrying the fire extinguisher.

Make sure the bracket holds it firmly in place in a position where it’s easy to access it and take it out. If you still find it smoking after using the fire extinguisher, call emergency services immediately.


Why Does a Car Stereo Smoke?

Reasons of Car Stereo Smoking

The smoke that we see coming out of an amp is most likely generated by a high fault current that’s overheating the insulation of the conductor.

When this happens… generally, fuses blow up inside the conductor.

This is to prevent a short circuit from happening. Fault currents are generated by faulty active components like tubes, and transistors, but shorted capacitors are also responsible at times. A shorted transformer can also produce plenty of smoke.

There can be several reasons behind your head unit blowing up. Such as:

  1. The output is shorted – this drives as much current as the power supply can output through the output transistors, causing them to fail. The way a MOSFET fails is different from how a BJT fails, and BJT’s fail 100% of the time with a shorted output if there are no measures taken by the manufacturer to prevent this (and in those cases, they fail anyway).
  2. The biasing circuit could get old, causing an increasing bias current in the output stage, eventually leading to failure. This means that something gets old and causes the amplifier to heat up and fail.
  3. The amplifier is operated in extreme heat – this prevents the heatsinks from dissipating enough heat, and the amplifier can easily fail.
  4. Valves tend to burn out like light bulbs. They can be quite fragile, so if are bumped just right, can fail at the next turn on.
  5. Other than this, there are often component failures where a component isn’t sufficiently spaced, say for example a 1/4 W resistor operating at 1/4 W all the time, or a 16 V capacitor operating at 16 V all the time. Or a transistor operating at high temperatures all the time. These components will eventually fail, causing smoking of some sort.

Whatever the reason, whenever the stereo blows up, it causes smoking.


What To Do If My Car Stereo Starts Smoking?

A car’s audio receiver, also known as its head unit, is the component in your car that allows you control over the entire stereo system, including the volume of the music and the equalizer settings.

Usually, it comes with a whole range of buttons and knobs and dials, or simply a touch screen to substitute for all that.

Some of these head units or receivers also have wireless connectivity options for your Bluetooth devices and are also satellite radio compatible. Regardless of the type, car stereos are standardized so that it’s easier to switch from a factory-installed form to a customized aftermarket receiver.

If you notice smoke coming out of your head unit while driving, at first turn off the radio unit, then pull over to a safe spot.

After you’ve extinguished the fire following the instructions above, try to find out the reason behind the fire. Find the user manual to know if it’s an aftermarket head unit or a factory-installed one.

Check The Installation

Things To Do When Car Stereo Starts Smoking - Reset Car Stereo

Typically, a car receiver smokes due to having electrical issues. Most commonly, it happens when there’s a short circuit somewhere in the wiring.

Thus, the next thing you need to do is disassemble the entire car audio system. No kidding, nothing can bring out a hidden problem with the wiring like disassembling can.

Now, pull out the head unit and check for power wires that might’ve been crossed. Look for any loose items. Especially, any unprotected wire end that might be in contact with the rear head unit.

Basically, anything that might have the possibility of disrupting the power supply from the car’s electrical system from getting to the head unit. After checking the power supply thoroughly, reassemble the head unit making sure that good and connected correctly.

You might also consider resetting the head unit. This is fairly easy to do. Just like any other electronic device, a head unit usually comes with a reset button.

It’s usually hidden underneath the faceplate in the front panel. Remove the faceplate and just press the reset button down. You might have to use the tip of a ballpoint pen to do this.

After that, the head unit will become fresh and free from any setting problems that might have occurred while you were handling it. Mind you, this would also lose any equalizer setting you may have set the head unit to.


Check The Wiring

Things To Do When Car Stereo Starts Smoking - Check Car Stereo Wiring

Carefully observe every bit of wire up and down closely for burn marks, breaks, corrosion, or any type of chew through damage caused by a rodent.

If you find any such area, cut out the damaged section, strip both the ends, and then solder them back together again. Use electrical tape to insulate the wire, or simply heat shrink it. You can buy heat shrink tubes at really affordable prices at hardware stores or online.

If you can’t see the damaged spot, the burn is most likely caused by a bad wire. In that case, replace the whole wire. Remember to get the correct gauge wire that fits with your car’s audio system.

In most cases, 18-gauge stranded wire is considered a standard for most car audios. It’s flexible and well-insulated and works great with car stereos.

Before installing new wires, check the power supply and the ground to make sure that they’re properly attached and have a good connection. You need to ensure that the ground connection is clean and uninterrupted.

Finally, even after hardwiring the head unit if it still smokes, then you’ll know that the problem is not with the wiring, but rather due to some issue with the unit itself. In that case, you should definitely contact a professional.


How Do I Prevent It from Happening?

Ways to Prevent Car Stereo from Smoking

Of course, short circuits and burnouts are unpredictable. But there are some precautions you can take to make sure your car stereo stays in good shape at all times to prevent it from smoking.

  1. If your head unit has a bad contact with the ground, that is, a bad connection between the chassis of the vehicle and the stereo system, then some amps might start to smoke. In this case, the best thing to do is to sand down the entire area, keep filing until it’s just the bare metal, and then mount the terminal holding the wires onto it.
  2. There could be a connection shortcut or loose connections. You can check this using a screwdriver to check that the wires inserted are securely in place on the terminal with the screw that was used for mounting it. Also, check that the speaker wires are not shorted out with each other because this is equally as important.
  3. The smoking could also be caused due to the size of the wiring kit being incorrect. Most people have the misconception about amps that it’s just a few wires here and there with a fuse holder on one end. But in reality, an amp is a much more complex device than that. Especially if you break it down to assembling the wires. You have to consider some basic factors of wiring such as the gauge. The general rule for this is the thicker, the better, but you need to ensure that it matches the requirements of the amp.


Some Final Words

You could go on searching the internet for preventions and cures for your car’s stereo smoking, but this will work only as a general guidebook. The best way to address any problems you might be facing with your car is to take the thing apart and take a good look inside the component that’s causing the problem.

However good instructions you may find on the net will never be as good as a professional diagnosis, especially when it comes to electrical issues. It’s always advisable to take a hands-on expert opinion before proceeding with any major changes or fixes to the car’s radio, stereo, or any other component.

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