Everyone loves listening to their favorite radio station or music when driving, especially when going out for a road trip or a long-distance drive. However, it can be quite frustrating when your car stereo system starts malfunctioning and you’ve already started the journey. There’re many things that can go wrong with your car stereo, especially when you’ve installed multiple audio components. At times, one component can malfunction and affect the entire sound system. Diagnosing the source of the problem can be quite challenging if you’re not used to handling the connections involved. Here’re some of the 10 common problems and solutions for your car stereo system:
1. The amplifier fails to turn on
If your car amp fails to turn on, then it might be having a problem. You don’t have to assume that it’s faulty and immediately buy a new one or send it for repair. The problem might be something minor that you can fix on your own. Maybe it’s a loose connection or an incorrect hookup. You should diagnose various causes of the failure before you assume that the amp is dead.
The first thing to do is no ensure that the amp is properly grounded. Confirm whether it’s hooked to a bare metal surface. The metallic plate it’s hooked onto should be rust-free and clean. In case the metallic plate looks dirty or rusty, clean it up. Scrubbing the metallic surface with a dry, stainless steel scrubber can remove the rust. Also, ensure the grounding connection is tight.
Also, ensure the remote cable is properly connected. It should be connected to the blue cable with white striping that comes from the stereo unit and not the solid blue cable. Also, ensure the power cable feeding the amp is tightly connected. Once you’ve confirmed that all that is okay, try powering it on. If it powers on, then you’re good. If it fails to turn on, then the problem might be an interior issue with the amp. Simply open it up and check whether there is anything that looks blown, especially the power supply. Blown MOSFETS are a common issue with amps. If you notice a blown part, then you can either repair it yourself if you know how to go about it or else take it to a local electronics repair center.
If the amplifier is turning on but going into protect mode, then it might be having an issue with low impedance due to speaker wiring issues or low power when the volume is turned all the way up. If the problem is not with the speaker wiring or turning up the volume, then the issue might be blown output transistors. To diagnose the problem, disconnect the power supply to the amp, then take a multimeter and ensure its set to ohms. Use it to measure the level of resistance that exists between the amp output transistors. A reading close to 0 should be okay but a reading of ~0 is an indicator of a problem with the transistors. Blown transistors should be replaced.
2. The amplifier is overheating and shutting down
A car amp can overheat and shut down. The reason behind this problem might be low impedance, extremely high gain or bass level, poor grounding, blown speakers, or speakers connected to the car chassis.
When the gain or bass levels are turned all the way up, then your amp may overheat and shut down. Also, if the input sensitivity is too high, the amp may overheat and shut down. Also, connecting speakers with lower impedance than the amplifier rating can lead to overheating and permanent amp damage. Ensure the gain and bass levels are not turned to their maximum.
If you have some car speakers that are grounded to your car chassis, or one of the speakers is blown, the amplifier will struggle to power the speaker. It’ll end up overheating and shut down. It’s advisable to power off the amp and avoid using it until you diagnose and fix the problem. Otherwise, using the amp when it’s overheating may get it blown. Check whether all the speakers are working. In case one speaker is not working, it might be blown and cause the issue. Disconnect any blown speaker. Also, check the grounding connection of the speakers and ensure any grounding is done properly.
Also, the problem might be using the wrong size of grounding and power cables. The best wire gauge for amp power and grounding should be 8 gauge and above. If it’s smaller, it can lead to overheating issues since the amplifier is not getting the much-needed power to feed the speakers. Also, the cables shouldn’t be more than 18” long.
In case you’ve ensured that everything is okay and the amp is still overheating, then you can invest in an external cooling fan. You can add several personal computer fans around the amplifier. They will keep your amp cool such that it won’t overheat.
3. The amplifier is cutting off and on repeatedly
If the amp is cutting off and on repeatedly, the issue might be a loose power connection or poor amp grounding. In this case, check the power connection and ensure it’s well connected. Also, ensure it is properly grounded. Again, ensure the grounding is done on a clean and rust-free metallic surface. The grounding connection should also be firm. When the amp is not properly grounded, you’ll even get a clipping sound in your speakers.
4. The car speakers are not working
If you’ve turned your head unit on and the speakers are not producing any sound, then you need to diagnose the cause of the problem. The first thing you should do is to check the speaker cable connections. Check the speaker cable connected to the sound source, be it an amp, radio, stereo CD player, or any other device you might be using. If all the speakers don’t have sound, maybe the cables connected to the amp or head unit are broken or loosely connected. It’s unlikely for all speakers to fail at the same time, hence the issue may be from the music player, radio, or whatever sound source you’re using.
You can simply get a wire and run it directly from the sound device to a specific speaker and test it. If you have an idle speaker somewhere, you can use it to test your car head unit without having to remove your car speaker. If there’s no sound after testing with another cable, then the problem is your head unit. If there’s sound after testing with another cable, then the problem is with your car speaker cabling. In this case, replace the cable.
If only one speaker is not working, then you need to check its wiring. You can remove the speaker and test it with an external wire connected directly to the head unit or amp. If it works, then its wiring has a problem and needs replacement. If it fails to work, then it’s probably blown and needs repair or replacement.
Also, if you have just connected new speakers and there’s no sound, you should check whether the polarity connections are done properly. Ensure the polarities are properly connected and that the speaker cables are firmly connected to the speaker and the head unit or amp.
5. Making a popping, buzzing, or crackling noise
In most cases, buzzing noise from speakers is a result of bass or gain being turned all the way up. Also, if something is touching the speaker cone, it might buzz as it vibrates. Thus, first, check whether your speaker cone is away from any item such as wires and other foreign objects that may be touching it. If any object is touching the cone, keep it away from the cone and test the speaker to assess whether the buzzing noise stops. If the buzzing noise doesn’t stop, check the gain or bass level and reduce it. If reducing the gain or bass level stops the buzzing noise, then it means your speaker can’t handle that much bass or gain.
Also, the buzzing noise may be due to a distorted voice coil or suspension. You need to check them and ensure they’re in good shape. If not, they might require repair or replacement. A grounding loop can also make your speakers buzz. A grounding loop is usually a result of a shared ground connection between multiple electrical devices. If this is the case, ground different devices to different metallic plates.
If your speaker is crackling and popping, then the amp might be too powerful for your speakers such that they can’t handle the power they’re receiving. The amp ends up sending continuous peak power to the speakers, hence they crackle and pop. Try connecting the speakers directly to the head unit without using the amp. If they still crackle and pop, they are probably blown and need repair or replacement. If they don’t crackle and pop after connecting them directly to the head unit, then you’ll need to upgrade to more powerful speakers.
6. The car radio won’t turn on
If your car radio doesn’t turn on, the first thing you should check is whether the power cable is properly connected or whether it’s passing current. You can use a multimeter to check whether the power cable is supplying power. In case it’s not, then the power cable is faulty and needs replacement. If it’s passing current but the radio won’t turn on, then maybe there’s a blown fuse in the radio. Test the fuse with a multimeter. If it’s blown, replace it. If it’s passing current, then your problem might be with the radio and it’ll need repair.
In case the radio is turning on and off, maybe it’s not getting enough current to operate it. If it’s turning off after bumping off something such as a road bump, then the problem is a loose power connection. Simply fix the cable firmly onto the radio and power source.
7. There’s sound but no bass
Bass is an essential part of the sound. It makes the music feel deeper and you’ll want your car to have the best bass. But what if you’ve just installed new speakers and you can’t get any bass? The most common cause of this problem may be a head unit that’s too weak to power the speakers hard enough for bass or there’s a bad speaker cable connection. First, ensure the terminals are properly connected. If there’s still no bass, then maybe you need to add a car amplifier to feed the speakers with enough power for bass.
8. The stereo is overheating
Besides an amplifier overheating, the stereo or head unit can also have overheating issues. If it’s overheating, the most likely cause of the problem is incorrect wiring. Check the entire wiring for any problems. Also, use the right cable gauge.
In case some cables have come into contact with each other and they’re not supposed to be in contact, then the stereo can overheat. If the stereo is still overheating, it might be having a burnt component that needs to be replaced. You can have it checked and repaired.
9. The stereo is not powering on
If your car stereo is not powering on, the first thing you should do is to check its power cable connection. Ensure the power cable is connected firmly in place. If it won’t power on when the power cable is fixed properly, then you’ll need to test whether the power cable is transmitting current. You can use a multimeter to check whether it’s transmitting current. If it’s not, then it’s probably damaged and needs to be replaced with a new cable. In case the power cable is transmitting current and the stereo is not powering on, then check whether its fuse is blown. Check the fuse with a multimeter to see whether or not it’s working. If it is working and the radio won’t power on, then you’ll need to have the stereo checked and repaired.
10. Sound is cutting off
If the sound from your speakers is cutting on and off, the most likely problem would be a loose speaker cable connection. Check the connection of the speaker cable from the amp. If it’s firmly connected, then check the connection on the speaker terminals. An overheating amp can also make the sound cuts on and off. You’ve already discovered how to diagnose and solve the issue of an overheating amp in the tips above.
With these tips in mind, you won’t have to rush your problematic sound device to a repair center. You’ll simply try to diagnose and solve the solution before parting away with some money at a local repair center. If you cannot solve an issue on your own, visit your nearest repair center. In case any part is blown or damaged, have it repaired or else replace your damaged audio device with a new unit.
Michael Evanchuk is a San Francisco-based sound engineer with 20 years’ experience installing, troubleshooting, and repairing commercial, automotive, and household sound equipment. Evanchuk owns an auto stereo center, where he offers highly competitive car audio installation and repair services. He has written dozens of articles on different sound engineering topics, all of which have been published in leading journals, blogs, and websites.