How to test car speaker wire with multimeter

There’s nothing worse than being in a mood to listen to your favourite music or binge-watch the latest show and hearing nothing coming from your speakers. It can be frustrating. Thankfully, you can take some easy steps to test your speaker wiring for faults and quickly fix this problem with the help of a multimeter.

Over time, speaker wires quickly become frayed or even broken from being moved around. This failure can lead to a distorted sound or, even worse, no sound at all. Unfortunately, even after examining the wire, it is often difficult to spot the problem. So how will you confirm that the wire is damaged if you don’t see it?

Possible Problems with Your Car Speakers & Wiring

How to test Car Speakers wire with Multimeter

If you are facing sound issues, there could be several possible issues.

Car wiring Connections:

Wires and connectors quickly become loose or even disconnected. Inspect the entire area to see if something needs to be appropriately connected. Aside from that, there could be issues with the speaker wires themselves. We will talk about how to test that in just one minute.

Speakers Grounding wire:

The ground wire might be loose or disconnected. Try relocating the wire to a stable location or securing it firmly. When the ground wire is to blame, you’ll hear a buzzing or whining sound in your audio system.

Car Amplifiers:

Check the settings for your amp. You’ll also want to secure the connections.

Car Speakers:

A blown speaker makes a distorted sound that most people have heard. This problem is not repairable, and you’ll have to replace the speaker. You might even be able to notice visible damage to the speaker.

Read more: How to test battery with a multimeter

Test Speaker Wiring with a Multimeter

1.   First of all Turn off All the Equipment:

This is a crucial safety step whenever you work with electronics. Otherwise, you can cause short or other damage to the components themselves. You don’t want to figure out multiple problems from a simple wire issue just because you chose not to turn off the power.

2.   Remove all the Speaker Wires:

First, remove all the wires from the box; this is important for both the positive and negative wires. Then, just press the two clips that hold the wire in or twist the connectors counterclockwise if that is your setup instead.

Your next step is to remove the wires from the stereo receiver. Do not attempt to remove the wire while the lock mechanism is still engaged. You may have to press clips together, use an electric screwdriver (like this one) or twist the lock to remove the wires.

3. Connect Wires:

Once you have removed the wiring from the stereo and the speaker, you are ready to create a circuit. Twist two separate cables together at one end. Now you have a closed circuit which is perfect for testing continuity.

Don’t twist the wire together tightly. You could end up having trouble separating the wire later, which can lead to damage.

4. Setup your Multimeter:

Turn on the multimeter and adjust the dial to the Ohms selection. You use this option to test resistance, which we’ll use on the speaker wires. Before testing the speakers, make sure the multimeter is working correctly. Touch the black and red probes to one another.

The reading should be 0 Ohms or no resistance. The reading indicates everything is working as it should. If you receive any other reading, there could be an issue with your multimeter. It might be time to invest in a new multimeter before proceeding forward.

5. Test Your Wire:

Touch the two probes of the multimeter to the bare speaker wires of the circuit. Make sure you do this on the two wires that you didn’t twist together. If your multimeter shows infinite resistance, then there is a break or cut somewhere along the wire. The wire indicates that it is time to replace your wire.

If the cable displays a small amount of resistance, everything works fine inside the speaker wire, and you have other sound issues.

Read more: How to test a Speaker with a Multimeter

Test Speakers Wiring with a Battery

If you find that the wiring works well, you could have an issue with the speaker itself. However, you could perform the test efficiently with a 9-volt battery.

  • Connect your 9-volt battery to the leads of your speaker. The positive gets connected to the positive of the battery end, while the negative should attach to the negative end. If the speaker begins to pulse, then the wire is working correctly.
  • If you see a pulse generates in the speaker, then the speaker is still functioning correctly.
  • You can do this same process to the tweeter speaker too.

Things to do:

  • Do not keep the 9-volt battery connected to your speaker for an extended amount of time, so this could lead to damage to the speaker.
  • Always perform a physical inspection of your multimeter before usage. If you notice any signs of damage, you need to assume it isn’t working correctly. To help keep the multimeter in good shape, always store your probes and unit in a protective case while not in use.
  • Also, you need to test the probes. There should be no physical damage, and all the connections should be secure. You can run your fingers across the probes to feel for damaged insulation, and this cannot be repaired and will require you to purchase new probes. It would be best if you never used a multimeter that has damage to the probes.

Safety Precautions

It is possible to face an electrical shock when working with any component that uses electricity. While it might not always be severe, it is something you need to be aware of.

Here are some steps you can take to minimize your chances of electrical shock.

  • Never work alone when doing electrical jobs. It is always wise to have someone with you.
  • Wear protective equipment as necessary. so this can include headwear and gloves. When working with exposed or currents more significant than 50 volts, it is always wise to use an insulated rubber mat.
  • Don’t take your measurement in humid or damp conditions.
  • Observe your multimeter closely and be aware of any signs that there is something wrong. Any irregularity could be unsafe.
  • Watch for anything in the atmosphere that could be hazardous. That includes flammable dust.

Just because you are working on a small electrical project doesn’t mean you aren’t at risk. It is always best to be safe when working around equipment that could hurt you.

Read more: How to test a car fuse with a multimeter

Frequently Asked Questions:

What happens if you connect car speaker wires backwards?

The most common result of connecting the speaker wire backwards is that the bass response becomes weaker. Due to the reversing polarity, bass frequencies suffer the most. It results in how a speaker’s cone produces bass tones.

Do positive and negative things matter to speakers?

Fortunately, connecting speaker wires in opposite polarity will not damage the speaker or the amplifier (assuming all the connections are proper). However, swapping the positive and negative speaker wires at the speaker or amplifier end will automatically alter the speaker’s polarity within the system.


It can be a burden trying to figure out what is wrong with your sound system, but it does not need to be. You can easily fix more issues with your speakers, and you can quickly fix the speaker wires. Grab your multimeter and test your speaker wiring, as this tends to be a common problem. If that doesn’t show anything, follow through with testing the other aspects of your system as well.

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