Car Speaker Not Working On One Side
(Last Updated On: May 23, 2020)

Car speakers tend to break or wear out over time. That’s especially true considering the kind of low-quality OE (original equipment) speakers that come with most cars.

However, when one of the speakers isn’t working on one side, it’s wrong to assume that the speaker is the problem. That’s because there are several components before the car speaker, and any of them could be the cause of the problem.

Here’s is a simple procedure to test your audio components to diagnose the problem and know how to fix it. These fixes also work for issues where the front car speakers are not working.

Diagnosing The Problem

For this article, we’ll assume that your car system has a  two-channel amplifier, a crossover, a head unit and two door speakers – with only the left working and right speaker not working.

As such, you’ll want to make sure that the speaker is the root of your problem before removing it. That’s especially if the speakers are behind the door panels.

Testing For Speaker Problems

To start testing the problem, turn off your vehicle and the car stereo system before disconnecting the speaker wires for the two speakers (right and left) from the amp.

Now connect your right speaker to the left amplifier output (which you know works). After that, switch on the stereo and ensure that the balance is on the middle position.

If the speaker isn’t working, then the problem might be anywhere between the speaker itself and the amplifier.

It could be a bad speaker, the speaker wires, or any other component in the wiring connections.

Additionally, if your speakers have a passive crossover between each speaker and the amp, that could also have a problem.Removing Your Car Speaker

At this point, you’ll need to take out the speaker from the door and use short temporary wires to test it on your amp.

That way, you can test the speakers and also check for bad wiring at the same time. That means if the speaker works with the new wires, then the problem is with your old wiring – in which case installing new wires will fix your problem.

However, if your speaker works when connected to the other amplifier channel, then the problem isn’t the speaker. In this case, you’ll need to turn off the stereo system and test the other components.

Check For Continuity

If the car speakers are mounted inside the door panels, then the space where the wires go through between the door frame and the door can be a point of failure.

car door speaker issue continuity

Though the wiring harnesses are normally sealed with hard rubber sheaths for protection, they tend to break over time. That’s mainly due to repeated stress when closing and opening the doors.

That said, you may want to check the continuity of your wires with the door open and closed.

If the wires lack continuity, then that means you have a broken wire somewhere. However, if you notice continuity to ground, then you have a shorted wire, and that might be the cause of your problem. Nonetheless, you still need to test other components if the wires are alright.

Ruling Out An Amplifier Problem

If your speaker isn’t blown, you’ll need to check your amp too. For example, some amps go into protect mode when the volume is turned up. Otherwise, you need to check whether the amp channel is bad, especially if all the speakers are connected to one amp.

To do that, put each speaker to its respective channel – the right speaker to the right channel and left speaker to the other one.

Keep in mind that the vehicle stereo should be switched off while you’re connecting the wires.

test amp in car

Once the speaker wiring is back to its original configuration, remove the RCA cables from the amp and switch them. That means the right cable should be hooked to the left input and vice-versa, before turning on your car stereo system.

If the right speaker still doesn’t work and the left one does, then you can start to suspect that the problem is with your amplifier.

That’s because you have eliminated the components before and after the amplifier. As such, if the problem was going through the right side of your system, then it should have shown on the left side when the cables were switched. In this case, have a professional repair technician check the amplifier.

If your right speaker is working after the switch and the left one doesn’t, that indicates the problem is anywhere before your amp.

It also shows that the problem lies along the right side of your system as the problem changed with the cable switch. The problem could be the cables or other components in the right channel. Switch off the stereo and plug the RCA cables to the original configuration.

Testing The RCA Cable Connection

For any components between the head unit and the amplifier, follow these steps to test each. In our case, only a crossover is present, so we’ll only need to do this once.

Start by checking the RCA cables connecting the intermediate component with your amplifier. Here is a step-by-step guide:

  • Unplug the RCA cables from component’s output
  • Plug the working speaker’s RCA cable to the non-working side of your car’s crossover. In this case, the left channel is the working side so plug the left RCA cable to the right side of the crossover.
  • Turn on your car stereo system

If the left channel keeps on working, then you should know that the RCA cables between the crossover and the amp are the problem.

However, if the left speaker is no longer working, then the problem isn’t the RCA cables. You can verify this by switching off the audio system and plugging the right RCA cable from your amplifier to the left RCA output of your crossover before turning on the stereo again.

If the RCA cables are not damaged, then you’ll have audio output from the right speaker. You should also ensure that you don’t skip the verification process as it’s possible that the problem exists in the cable and other components.

Additionally, make sure you turn off the stereo and restore the original connection of the RCA cables after you’re done testing.

Checking For An Equalizer Or Crossover Problem

Whenever you find yourself in a situation where one stereo speaker is not working, tis important that you set the correct crossover and phase on your subwoofer.

Checking For An Equalizer Or Crossover Problem car door speaker not working

At the intermediate component’s input (the crossover in this case), interchange the RCA cables – the right to the left input and vice versa – and switch on the audio system.

If the left channel continues working and the right channel doesn’t work, then the intermediate component is the problem. In that case, consider repairing or replacing the component.

If the problem shifts to the left speaker and the right speaker is now working, then that shows the crossover isn’t the problem. In that case, consider checking the components before the crossover. But first, turn off the stereo and fix the RCA cables to the original configuration.

Testing The Head Unit

Most people will easily conclude that the speaker is the problem if the head unit is turning on fine, but they don’t get sound from any of the speakers.

check car head unit car speaker not working on one side

However, that’s not always the case. The fact that your head unit is switching on doesn’t indicate that it’s working properly.

For that, you’ll need to do some tests to rule it out. But before you do that, here are some things you’ll want to do:

  • Verify that your head unit is not in anti-theft mode which requires a vehicle radio code
  • Test different audio inputs such as CD player, radio and auxiliary input, to name a few
  • Check the fade, pan, and volume settings
  • Check for unplugged or loose wires
  • Test any onboard switches

How To Test The Head Unit

Start by taking out the head unit from your dashboard to get access to the RCA cables.

After that, unplug both cables from the unit and be careful not to disconnect any other wires. Take the left cable and plug it to the right channel of the unit and turn the system on.How To Test The Head Unit

If the left speaker is still working, then the problem isn’t in the head unit. That shows the problems is in the cables connecting the head unit with the intermediate component (if your car has one) or the amplifier.

You can confirm that by switching off the stereo system to unplug the left RCA cable and plug in the right RCA cable to the left stereo output. The speaker will not give any output, indicating that the RCA cable is faulty.

However, if the left speaker stops working after plugging it on the right channel, then your head unit has a problem.

You should confirm this by switching off the stereo, unplugging the left RCA and fixing the right RCA cable on the left output of your system.

The right speaker should start working when you turn on the audio system, but if it doesn’t, then it shows you have a faulty RCA cable and a spoilt head unit. That’s rare, but not entirely impossible. If the head unit is faulty, you can easily pick up a good one here.

Wrap Up

So there are the fixes whenever you find your car speaker not working on one side. These fixes will also work when the front car speakers are not working.

There you have it, that’s the troubleshooting procedure that most technicians use to fix stereo system whenever such a problem occurs.

It may require some time and a few basic skills, but its worth a try if you don’t want to take your car to a technician. However, you should consider calling in a professional audio expert if you still can’t diagnose the problem after following the testing procedure above.