Car Stereo Has Power but No Sound from Speakers
You turn your head unit on, it lights up, and you twist the volume knob.
Everything seems normal but you don’t get any sound from the speakers.
It’s a frustrating situation to be in – everything seems fine, but for some reason, the thing just won’t fire up. Why?
Well, there are a ton of things that could make your head unit turn on, but no sound is coming from the speakers. The issue could be related to the amp if you have an external or a factory amplifier, to the speaker wires, to the audio settings or to the head unit itself.
Since each car sound system is built differently, it’s difficult to say exactly what your problem is without knowing some more information about your stereo system. For this reason, we’ve compiled an exhaustive list of the most important things you need to check to get the problem resolved quickly and with the minimum amount of inconvenience.
Without any further ado, here’s how to troubleshoot your car stereo if you aren’t getting any sound from the speakers.
How to Fix a Radio That Has Power but No Sound
Driving a car without sound is an odd experience; you won’t notice how important sound is until it’s gone. You essentially lose a chunk of your driving experience,
So, what’s the answer?
Several things can be checked, from accidentally muted audio to a defective unit. If a simple switch on/off doesn’t fix things, here are several possible issues, and a fix for each.
This article is divided into two sections. In the first, we cover all the things you need to check if your speakers are driven by the headunit only. In the second section, we cover all the additional things you should check if you have an amplified stereo system.
Part 1: Speakers Powered by the Headunit
1. Incorrect Settings
This seems obvious, but I can’t tell you how many times I’ve accidentally muted the volume on my headunit only to slap my forehead in exasperation later.
This can happen easily by just pressing the mute button or by lowering the system volume too much.
This may be elementary, but it never hurts to be thorough.
2. Blown Speaker
If your headunit has been working fine, but all of a sudden all the speakers just stopped working, then it’s highly likely you have a blown speaker.
If you have a blown or grounded out speaker, your head unit will light up and even play CDs, but it won’t give out any sound. This is because its internal amplifier is in protect mode.
Yes, you heard that right. Just like amplifiers have a protect mode, head units also have one. Unfortunately, when a headunit goes into protection mode, you typically don’t see anything which indicates so such as a blinking red indicator
So, basically, what you need to do is to check all of your speakers one by one using a multimeter.
To check a speaker, set your multimeter to ohms and touch the leads of the multimeter to the speaker terminals.
If the multimeter reads 1.0 ohms, the speaker is working. If it displays a reading of infinite ohms, the speaker has been blown.
If none of your speakers is blown, make sure they’re all tightly mounted in their mounting holes. This is because if, for some reason, any of your speakers magnet for instance is touching the door metal, you won’t get any sound from your speakers.
3. Shorted Speaker Wires
Speaker wires run through the cabin, and connect each speaker to the head unit (or the amplifier).
So, if your car stereo turns on, but you’re not getting sound (or you are getting sound from just one or two speakers), the culprit is most likely a speaker wire that’s been damaged, or a speaker wire that’s loose and is touching metal causing the speaker to short out.
4. Blown Headunit Fuse
A car stereo that won’t turn on but it has power (it lights up) is a probable sign of a blown fuse. This sounds counter-intuitive, right? How can a headunit light up if its fuse is blown?
Well, here’s the thing: although fuses are either good or burnt out, there are rare situations where a fuse can fail but still maintain electrical contact that breaks intermittently.
Most head units – especially aftermarket ones – have a built-in fuse, typically located on the back side. Factory stereos’ fuse is usually located in your vehicle’s main or accessory fuse block.
You can test your radio’s fuse by visually inspecting it or by using a multimeter. The latter is the best way to go about it because it is possible for a fuse to fail in such a way that it is difficult to tell one way or the other simply by looking at it.
5. Faulty Unit
If everything checks out okay, but you still couldn’t figure out the root cause, it is more than likely that the problem lies within the head unit itself. A defective head unit should be sent into the manufacturer for repairs if it’s still under warranty, or find a local repair shop that can diagnose the problem for you. With any luck, you’ll be jamming again in no time.
Part 2: Speakers Powered by an Amplifier
If your car has an amplified system, or if you’ve installed an external amplifier yourself, here’s a list of things that you should also consider checking.
If you haven’t installed an external amplifier in your vehicle, that doesn’t mean there isn’t amplifier powering your speakers without you being aware of.
Most vehicles come equipped with a factory amplifier that’s hidden somewhere under the dash, in the side kick panel, under the passenger seat, in the trunk, or under the rear seats …etc.
If you couldn’t figure out where your factory amp is mounted, or whether you car has one or not, google is your friend.
1. No Remote Turn on Wire
A remote turn on wire is a blue wire (typically with a white stripe) that’s located behind the head unit. It’s responsible for turning your amplifier on and off.
Basically, when the headunit is powered up, a +12 volts DC signal is sent through the turn on wire to the amplifier’s turn on circuit; when the amplifier senses this voltage, it turns on. Likewise, when the headunit is switched off, the remote turn on wire stops transferring the signal/voltage and the amplifier turns off as a result.
If this wire is damaged, or if it isn’t installed correctly, your amplifier won’t turn on even if it has good power and ground connections. And as a result, you won’t get any sound from your speakers.
When installing a new aftermarket headunit, most inexperienced guys left this wire unattached, resulting in no sound from speakers.
It should be noted that most car stereo’s harnesses also have a solid blue wire. This wire is typically for power antenna or factory amplifier turn on, do not confused it with the remote turn on wire with the blue/white stripe.
If you use a power antenna wire (solid blue wire) in place of remote turn on wire (Blue wire with a white stripe), your amplifier will turn on only when the radio is in AM/FM mode. If you switch to CD, SD Card, Aux input, Bluetooth etc… the power antenna wire will stop receiving power and your amplifier will power down as a result.
2. Amp in Protect Mode
Protection mode is essentially just a shutdown state that car amplifiers can go into under a number of different circumstances to prevent serious damage to the amp or other components in the system. It’s basically the electrical engineering version of the COVID-19 lockdown.
So, if your amplifier is in protect mode for whatever reason, you won’t get any sound from the speakers until the amplifier is restored to its normal operating condition.
Car amplifiers go into protect mode for a wide variety of reasons including but no limited to :
- Load mismatch (amp overloaded)
- Overheating (thermal overload)
- Bad ground
- Faulty speaker, subwoofer, cable or another component
- Loose speaker wire
- Wrong amp wiring
- Faulty amplifier
3. Improper Grounding
A bad ground can cause all sorts of problems that you can think of including but not limited to clipping, overheating, ground loop noise (engine whine), amp damage …etc.
Technically speaking, what grounding an amplifier does is that it completes the electrical circuit powering your amplifier. Therefore, if your amp is not properly grounded, it may fail to turn on, hence you won’t get any sound from the speakers a result.
So, trace your ground wire to where it’s attached to the chassis. Check if it has any damage, tears, kinks…etc. If the wire appears in good shape, check the connection point. If the ground itself is loose and allowed to move in the slightest, the amplifier will be cutting in and out randomly.
For proper amp grounding, always ensure your ground wire is the same exact size as the power cable, and that it’s attached directly to a part of the metal chassis that is sanded down and scraped clean of any paint or primer.
The ground connection should be preferably within eighteen inches of the amplifier’s location.
4. Blown Amp Fuse
Fuses exist to prevent too much current from overloading a circuit and causing an electrical fire. For this reason, your amplifier uses a built in fuse. In some installations, you’ll also have an additional in-line fuse located somewhere on the power wire. Furthermore, if your amplifier gets the power from a distribution block, the latter also has a fuse of its own.
So, depending on how an amplifier is wired into the electrical system, you can find yourself dealing with a variety of different fuses.
If any of these fuses are blown, that may be the reason why you are not getting any sound from the speakers. So you will want to replace the blown fuse to see if that fixes the problem.
5. Chafed Power Wire
It goes without saying that if your power and ground wires are not thick enough to accommodate the amp’s demand for electrical current, the amp won’t power on, therefore you will get no sound since all the speakers are powered by the amp.
So, if everything checks out okay, ensure your amp power wire isn’t loose, corroded, or shorted out somewhere. In some cases, a partially chafed power cable may only make contact with the ground when you’re driving or when you run over speed bumps or rough terrain, making the amp cut in and out, which in turn results in intermittent sound or no sound at all.
6. Amplifier Mounted to a Conductive Surface
Last but not least, check if your amplifier isn’t mounted to a conductive surface. If the case of the amplifier is in direct contact with the metal of the vehicle, either directly through the case or through the mounting screws touching metal, the amplifier will either go into protect mode or it may not turn on at all. In either case, you will get no sound from the speakers.
So, to ensure the amp is not touching any conductive surface of the vehicle, mount it onto a wooden board or plastic panel and then attach that wherever you want in your car, or simply isolate your amp’s case using rubber grommets around the mounting screws.
There’s no denying that driving a car without sound is an odd experience; you won’t actually notice how important sound is until it’s gone. You essentially lose a chunk of your driving experience.
So, if your car radio seems to be working, but no sound is coming from the speakers, the steps we listed above should help you quickly fix the problem with the minimum amount of inconvenience.
If you couldn’t fix the problem yourself, feel free to contact us. We would love to see how we can help out!