Listening to music, a podcast, or an audiobook is a great way to avoid boredom and will actually keep you more focused and attentive when driving, while also keeping the passengers entertained. Turning on the radio only to not hear any sound coming out of the speakers can be frustrating, but in this guide, I’ll take you through the steps to get your radio working again.
When the car stereo has no sound coming out of the speakers, the most common issue is a blown fuse, followed by loose wiring, especially with aftermarket stereo systems.
How Does a Car Stereo Work?
I won’t burden you with the details, but it’s important to understand how car stereo works. First, we’ll go through the list of components:
- The head unit is the face of the radio with controls, dials, or a touchscreen. It contains all the hardware and software necessary for file reading, USB, AUX, and Bluetooth connections, as well as volume controls.
- The amplifier does exactly what the name implies – it amplifies the signal coming from the head unit to make the sound coming from the speakers louder. Most aftermarket and stock head units come with a pre-amp, which is powerful enough to drive a basic set of speakers.
- Speakers transform the signal to create air vibrations which we experience as sound.
- Wiring connects the head unit to the antenna, amplifier, and car battery. The amplifier, if present, is connected to the car battery and all of the speakers inside the vehicle.
Now that you’re familiar with the components, you can already make your guess as to what is causing the lack of sound. To make things easier, I’ll cover all causes and if possible, the DIY methods of fixing them.
1. Blown Fuse
Whenever you’re dealing with an electrical problem, you should always begin your inspection with the fuse box. It doesn’t matter if it’s the windscreen wipers, headlights, or the car stereo – fuses are very easy to check and the best problem to have, considering how cheap they are.
Fuse boxes have no universal mounting spot, so to find yours, do a quick google image search. It can be located inside the engine bay, next to the battery, or below the windshield, underneath a protective cover. The fuse box can also be below the steering wheel, on the left side of the front cabin divider, or underneath the center armrest.
Once you’ve found the fuse box, you can use a test lamp to tap the metal dots on top of the fuses to check if they’re working. Alternatively, you can pluck each fuse one by one, and see if the metal wire running through the center has cracked.
Any blown fuse should be replaced by a new one of the same rating. For a few dollars, you can get an entire spare fuse kit that includes a fuse plucker to make it easier to get the fuses in and out of the sockets.
Once all of the fuses have been swapped, turn on the radio and check if the sound is coming from the speakers. If it isn’t, you’ve likely solved some other electrical problem you didn’t even know you had, like a blown rear fog lamp fuse or something rarely used. After you replace fuses, it’s a good idea to keep an eye on them to see if they will blow again in the following days. Fuses can fail randomly, but repeated failures indicate a shortage in the electrical system.
2. Loose Wiring
Failure of stereo wiring is very unlikely, even if the car is decades old. The more likely problem would be wiring becoming loose due to vibrations and bumps caused by regular driving.
Loose Head Unit Wiring
To check the wiring of the head unit, you must first gain access to the backside. This is not as easy as you may think, because car stereos are deliberately difficult to remove as an anti-theft measure. I’m going to link to a video that explains how to remove an aftermarket stereo, but you’ll have to do your own research to find a way to get yours detached without damaging the dashboard or the head unit.
Slowly pull the head unit back just enough for it to tilt out of the dashboard. Check every wire and connector to see if they’ve become loose, and more importantly see if there are any loose connectors inside the dashboard. Keep in mind that they could be deliberately left disconnected, so check the installation manual for your head unit for the exact number and type of connectors it takes. Once you’re done, turn on the stereo and see if it works, and then put the head unit back in its place.
Loose Amplifier Wires
Just like the head unit, the amplifier has a number of wires going in and out towards the speakers. Inspect the connectors and see if there’s anything wrong with them. Interestingly, the amplifier is usually placed in the back of the vehicle, inside the cargo compartment. Do a bit of research and find out where exactly to look.
Loose Speaker Wires
The final destination for all stereo wiring is the speakers. I haven’t heard of a case where a disconnected speaker would cause the entire stereo system to shut off, so this cause is more appropriate for single speaker issues. To find the faulty speaker, play with the fader and balance to zone out parts of the car – left and right, back and front.
Then bring your ear to the remaining speakers and find the one that is not emmiting sound. Carefully remove the speaker cover with a flathead screwdriver, and check the wires. To reconnect a loose wire, you’ll need a soldering station. It’s not the cheapest tool, but it’ll still be cheaper than spending gas, time, and money on an electrician. Plus, you get to keep it and use it for future repairs.
3. Failed Amplifier or Preamp
Because the amplifier is in charge of making the stereo signal usable by the speakers, when it fails, you can expect a lack of sound, distortion, or weird noise coming from the speakers.
Some preamps cannot be separated from the head unit, and if it is possible to replace it, it could be difficult to find a used preamp that isn’t sold in a package with a head unit. With the full amplifier, you’re in luck, as it’s independent and can generally be swapped with whatever option you like. Just keep in mind the number of channels and specifications of the amplifier you’re replacing.
4. Software Issue
Sometimes, you just have to re-initialize the stereo software to get it working again.
Like a phone or a computer, even a car stereo can glitch out and malfunction. By flashing the memory, your stereo should restart as if it was turned on for the first time, which will hopefully solve the issue. It’s possible the someone with access to the car played with the settings and messed up the audio balancing, so you can check the settings before flashing the memory to save your data.
Is there a fuse for car speakers?
Car speakers don’t always have a fuse, but the head unit and amplifier do. If a short happens anywhere in the system, the fuse will be blown to prevent damage and electricity-cause fire.
Can a blown fuse cause speakers to not work?
Yes, because the fuse is an intentional weak spot in the electrical system. If there’s a power surge or a short, the fuse will fail and disconnect the circuit to prevent any other, far more expensive component from failing. Fuses can fail randomly, but they usually indicate a problem with the wiring or power supply.
Why is one of my speakers not working?
Check the balancing settings of the stereo system, because car stereo allows you to completely shut off sound from either side. If that’s not the cause, then it’s either loose wiring of the speaker or the speaker itself has failed.
Why does my radio have power but no sound?
In this guide, I’ve explained every cause for lack of sound with a functional stereo. The one last thing I should mention is the mute button – you might have pressed it to take a phone call and forgot to turn the volume back on.
Can a fuse blow for no reason?
Even though they’re quite reliable, it’s possible for a fuse to blow randomly like any other component. As I’ve mentioned before, you should still keep an eye on the fuses to be certain it was a random failure and not an electrical problem.
How long do fuses last in a car?
Car fuses can last years if not decades without ever failing, provided that the fuse box is kept dry, and there are no imperfections in the electrical wiring and components.
If you’re not getting any sound from the speakers while the stereo appears to work just fine, check the fuse box and wiring. If neither is responsible for the problem, it could be that the preamp or amplifier has failed and needs to be replaced. Before purchasing a new unit, reset the stereo settings to make sure it’s not a software issue.