What To Do If An Aftermarket Car Stereo Won’t Turn On?

You turn the car on and start the stereo but no matter how much you try; you just can’t get the stereo to work?  Aftermarket stereos can be a pain if they aren’t functioning properly. Whether it’s an installation that might not have gone as planned or a random problem that comes out of nowhere.

Purchasing high-quality components for car stereos is a good way of avoiding some common car stereo problems. However, any car stereo will sooner or later experience problems. Unfortunately, if your car radio suddenly stops working, you have to pay an expensive repair bill or even replace the device completely.

But the positive side of this particular situation is that if you approach it methodically, you are actually dealing with a problem that you can get to the bottom of and solve. If you are lucky, you can even fix it yourself. Don’t worry here is a list of your common car stereo problems and their solutions to help get your stereo up and running!

An Aftermarket Car Stereo Won’t Turn On

Problems And Their Solutions That Cause Your Car Stereo won’t Turn On

Here are some problems that cause your car stereo not to turn on and their solutions are also provided.

Problem 1. Can’t Find an Accessory/Ignition Power Wire

In some cases, car stereos do not come wired with a 12v Accessory/Ignition wire, making an aftermarket radio difficult to install and work properly. Many Jeeps and Chevrolet systems have a data signal wire that carries a very low voltage signal that tells the OEM Head Unit when to turn on, however; it is not compatible with aftermarket units.

Possible Solution

  • . The easiest way to locate an Accessory/Ignition wire is to find a cigarette lighter that turns on when the car does. Get behind the lighter and tap into the positive wire and connect it to your RED Accessory/Ignition wire on your aftermarket wire harness.

Problem 2. Head Unit Has Power But No Sound

Head Unit Has Power But No Sound




If you are finding that power cuts out in your recently installed aftermarket head unit, it’s highly likely that the head unit is not receiving 12V.

Possible Solution

  • Many cars have built-in amplifiers that require a 12v signal to be sent in order to turn on the Amplifier, the most common being Bose, Infinity, and JBL. If your car has any of these systems, check your AMP TURN ON signal wire for 12v. Blue/White wire located on Head Unite wire harness.

Problem 3. Installed An Aftermarket Head Unit and Now It Has No Power

Possible Solution

  • First off, check your wiring. If you have a voltage meter or a test light, test the ground (black), constant 12v (yellow), and accessory 12v (red) wires to make see if you have the correct voltage in the correct wires, as well as a good ground. Constant will always be 12v, whether or not your car is on. The accessory will be 12v only when you turn the key to the “ON” position or the car is running. Make sure to use your ground, as well as another ground (like the frame or body of the car) while testing your constant and accessory to test that you have a good ground.
  • If you find that one of your power wires or ground wires is not correct, check your vehicle wire diagram and make sure you have the correct corresponding power and ground wires.
  • If you do not have power, and you know for a fact your wiring is correct, check the fuses under the dash or under the hood (depending on your vehicle). The easiest way to locate the correct fuse is to look in the Owner’s Manual and find the fuse number and box location. Your manual should indicate which fuse is for the “Accessory”, “Car Stereo”, or something of that sort. After finding the location of the fuse, pull it and make sure that the leads are not corroded and that the fuse has not been broken or popped.
  • If your speakers randomly stopped working and you noticed that your amplifier is in protection mode, there are a few reasons why this might have happened.
  • Most aftermarket amplifiers have protection from low and high voltage. If your alternator is producing too much power, it will trigger the amplifier’s protection mode. Vice versa, if your battery is low and the amplifier is not receiving a constant 12v, it will enter protection mode.
  • Amplifiers will also enter protection mode if there is a short somewhere. If you have a signal RCA wire that is shorting out, this could be your problem so check to see if your RCAs are in-tact and not shorted. Also, if one of the output channels is shorted out, or you have a blown speaker, many aftermarket amplifiers will enter protection mode. Disconnect all output channels and see if they will return to normal operation.

Problem 4. No Bass from Car Speakers

No Bass from Car Speakers


We know it’s all about that bass, but what happens when you’re not actually getting any bass? This is a car stereo problem that usually occurs when factory speakers are being upgraded or aftermarket speakers are being installed or repaired.

Possible Solution

  • Check whether the speaker wires are connected to the stereo amp and head unit appropriately.
  • The positive (+) terminal of the speaker should be connected to the positive terminal of any other component, including the battery. The same case applies to the negative (-) terminal.
  • Another potential solution is installing an external amplifier. Some people opt to have a head unit upgrade to solve the no bass problem.
  • The bottom line is that your car stereo needs something that puts in more watts.

Problem 5. Alternator Wine

If you hear a whining noise that fluctuates with the RPMs of your vehicle and lessens when the car engine is turned off, you are dealing with Alternator Wine.

Alternator Wine is caused by having bad ground to either your head unit or your speakers’ amplifier. Check your ground wires and find a better place to ground them, e.g. the frame or body of the car.

If you are experiencing headlight dimming when you have your radio turned up with aftermarket amplifiers and subwoofers, your stereo is pulling too much power for the alternator to keep up.

Possible Solution

  • Wire in a Capacitor. Although curing headlight dim is far down on the list for a Capacitor’s use, a capacitor might be the solution to your problem. A capacitor is made to curve the spikes in power from the battery to the Amplifier, to create consistent 12v power. Adding a capacitor with the correct farad, in some cases, will curve your amplifier power drawing spikes enough to limit headlight dim. The rule of thumb farad–wattage conversion is 1 farad to every 1000 watts.
  • Upgrade the Alternator. Sometimes OEM alternators don’t generate enough power for your upgraded stereo. Upgrading the alternator to one that can produce enough power to handle your upgraded amplifiers/stereo will solve your headlight dim.
  • Get a Bigger/Better Battery: Sometimes old/cheap batteries can be one of the sources in your headlight dim issue. Replace your battery with a newer, bigger batter to handle more power and load. Although this might not fix the problem it might help.
  • Add an Auxiliary Battery: Wire in a completely separate battery to power just your stereo. This will lessen the load on your engine battery and sometimes will fix your headlight dim.

Problem 6. Installed a Car Stereo, Now Radio Doesn’t Have Signal

If you installed a new head unit in your car, and you’re now noticing that your car’s radio has an abnormal amount of static, you may have wired the unit incorrectly.

Possible Solution

  • Pull out the new car stereo to gain access to the wires again. Look for a blue wire on the aftermarket head unit and ensure that it’s connected to a corresponding wire within your vehicle’s wire harness. The Blue or Blue/White wire on your aftermarket head unit is what powers a powered antenna. Without the power, your vehicle’s antenna is significantly less powerful and will result in static.

Problem 7. Car Headlights Flicker When Music Is Turned Up Loud

If you recently installed a stereo with an amplifier(s) and subwoofers, your alternator and battery may not be powerful enough to handle the additional power that’s being pulled when your stereo is turned to high volumes.

Possible Solution

  • Check your battery – is your battery fresh? Have one of your local auto stores like O’Reilly Auto Parts do a load test on it. Your battery may be on its way out.
  • Compare the output of your alternator with the power demands of the stereo or components that you added to your car. You may need an upgraded alternator.
  • Get a capacitor – capacitors store battery to curve the power demand spikes on your battery and alternator. This can help tremendously but requires you to buy and wire in an additional component to your system.

Problem 8. Car Stereo Becomes Too Hot

Faulty wiring is the major cause of car stereo getting unusually hot. Your speakers could be incorrectly wired, or wires that are supposed to run separately have been combined.

There is no problem with the system getting warm since various electrical devices heat up while in use. That is to be expected. However, the generation of too much heat could be an indication of a malfunction.

It is important to note that abnormal buildup of heat can be dangerous. The heat can damage various parts of the car stereo and even cause a fire.

Possible Solution

  • You probably need to check the entire installation and wiring of the car audio system. If you do not find any installation or wiring faults and the stereo still runs hot, the ultimate solution might be servicing the entire system.

Problem 9. Car Stereo Problems Due to Poor Grounding

The majority of non-equipment-related audio problems result from poorly chosen ground points. Apart from alternator whine, poor grounding can cause the amplifier to clip.

Poor grounding can cause the amp to cut in and out. When the car stereo is turned up, the amps pull more current. If the system has an unreliable ground, the amp cannot pull the needed current. This normally sends the amp into clipping.

Possible Solution

  • As you check the integrity of other connections, always remember that grounding is of utmost importance.
  • If you install a large car audio system, it will require a bigger ground. Also important to remember is that grounds should be on the car’s chassis.
  • Many people make the mistake of using the negative battery post as a ground for the car audio
  • This is a terrible idea as the entire ripple from various items including the alternator travels through this point.
  • Using it as a ground invites all the noise from these items into the sound system. You definitely do not want that.


The stereo is the heart of your car’s sound system. Without it, your in-car entertainment is rarely enjoyable. For music lovers, especially, driving a car without tunes is unimaginable.

The bottom line is that lack of proper maintenance can result in your car stereo having problems like those described here. To ensure your sound system is working the way it should, consider a full diagnostic of the system.

When you know how to identify and solve common car stereo problems, you reap the best reward of all, superior sound and a quality ride. We hope you found this guide helpful.


Why is my aftermarket stereo not working?
The radio is connected to the power source and speakers through wires that are mostly found underneath the dashboard. If there’s a problem in the wiring, the radio will definitely not work. Blown fuses are another common culprit. If the fuse is blown, the car’s audio circuit is broken and the radio cannot turn on.
What do you do if your stereo won’t turn on?
Check if there’s a light indicator on your stereo system after you complete each step. If you need model-specific information to complete any step, check your manual. 1. Securely plug your device to a working wall outlet. • Remove any surge protector. • If it still won’t turn on, try a different wall outlet. • Make sure that your device is set to the correct voltage for your area. • Some devices have a 110 to 220 voltage switch where the default setting is 220V. Verify that this switch is set to 110V. 2. Press and hold the POWER button, and unplug it from the wall outlet at the same time. 3. Release the POWER button. • If you haven’t used your device for more than three hours with the volume set at a high level, unplug it for one to two hours to reset any output generators inside the unit to avoid overheating and further damage. 4. Make sure that your device has enough ventilation. 5. Plug your device back into a wall outlet 6. Turn on your device. 7. If applicable, reset your device.
How do I reset my aftermarket car stereo?
Devices with a reset button: • Remove the faceplate from your car stereo. • Press the RESET button on the front panel using a pointed object, such as a ball-point pen. Note: • These steps are for the in-dash car stereo receivers that have removable faceplates and may vary slightly based on your specific model number. • For car stereos that have Bluetooth® wireless features, it would be necessary to perform the BT Initialize procedure to completely reset it. Devices without a reset button • Depending on your car stereo, press DSPL and (back) /MODE, DSLP and CALL button, or SOURCE/OFF button for more than two seconds. • Turn on your car stereo.
How do you test an aftermarket radio?
Take your red and yellow wire from the stereo harness attach it to the positive (+)terminal on your car battery. Then take the black wire from your stereo harness and stretch it to the negative (-) terminal in your car battery of the stereo is good it should power on. Attach speakers to test the audio output.


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