How to Tell Which Auto Speaker Wire Is Positive With an Ohmmeter

Auto speakers are in the car audio system, which is difficult to work with, so you need some skills. When wiring the system, you have to tackle the engine bay to work with the speaker since the engine is powering the speaker. In this process, you can do many different ways but choose to use the multimeter method and 9 volts which are the best.

Normally you need to remove the panels and other components of the speaker to access everything. When working with the speaker, you need to troubleshoot the systems carefully by testing the speaker to the ground using a multimeter since it produces accurate results.

Therefore, if you are not sure of what it takes to test the polarity of the auto speaker system wires, then you should not worry since this post will describe the steps you need to work with for a successful process.

How to tell which auto speaker wire is positive with an ohmmeter

how to tell which auto speaker wire is positive with ohm meter

Before narrowing down to the steps of testing the polarity of the speaker wire, you need first to state what it means by the speaker wire polarity and how it works in the auto speaker. Below is a description of the speaker polarity:

Speaker wire polarity refers to how the connected positive and negative terminal on an audio system. The speakers sometimes have positive or negative signs or rather a red probe and a black probe.

After getting the idea of speaker polarity, you need to know how it works and what can be used to check for the speaker polarity. In this case, we are using the multimeter such that we have the analog multimeter and the digital multimeter.Analog multimeters are best for testing the polarity since they contain the meters that measure the values continuously. However, there are digital multimeters, but they lack the meters to display the resistance in ohms but instead produce a beeping sound. But all the multimeters are good for use depending on the user’s knowledge.

Techniques to use;

Method  functions Essential products
Using a Multimeter       gets accurate display results multimeter

Steps of telling which auto speaker is positive using the ohm reader

Steps of telling which auto speaker is positive using the ohm reader

Tools needed

  • Multimeter
  • Harness for speakers wiring

1. Disconnect the speaker

Disconnecting the speaker means removing the speaker components like the wires or the clamps holding it. You can also remove the panels or rather cabinets depending on the type of your system and how the parts connect to it.

2. Switch off all the power sources

Ensure you switch off all the power sources from the car, like the interior lights and other smart devices that you only need to remove the cables that are holding them. With this step, you need to cover yourself from getting shocked while working on the wires using an antistatic wrap

3. Connect the wires to the battery

Choose to use direct current voltage or alternating current voltage to set on your multimeter. In most cases, the battery power is in direct current so you need to use this setting since the car runs on the battery power.

4. Touch the probes with the ground wire and speaker terminal.

At this step, you need to touch the red probe to the ground wire or any car metal, then touch the other black probe to each speaker terminal. If the speaker wires and other components are working correctly, there could be a possibility that the reading will be similar to how the wires are connected. However, suppose the speakers are connected in an anticlockwise direction. In that case, your reading must be positive, but if they are in a clockwise direction, you will see that the reading is negative.

5. Check the similarity of the results for all the speakers

Repeat the steps above with all the speakers in your audio system and compare the results to check how the wires work. Check your car since some have one positive and negative wire that comes into the speaker while some have two positive and negative wires coming to each speaker. Therefore, ensure you connect each probe separately to a positive and negative wire.

6. Replace the faulty parts and fix any damages

Check for any faulty parts with your car audio system that you need to replace if they are faulty so that you can get sweet music. Check the continuity of the terminals that if they are not continuous, the problem can be with the speaker itself or the speaker wiring.

Replace all the cases, including wiring issues, for the speaker to work correctly and produce a loud sound, then you need to reconnect everything to its position.

Frequently asked questions;

  • What is the best battery voltage for testing car speaker wire polarity?

The best battery voltage for testing the speaker wire polarity is the nine-volt battery that is fine, and you only need to take it out of the car before using it for tests.

  • Is it important to check which speaker is positive?

It is good to check if the speaker is positive since most speakers are polarized so that the positive wire will send a signal to one of the parts in the speaker cone that can move forward and push air out of the back.

  • Is there an effect of mixing the positive and negative speaker wire?

When you mix the positive and negative speaker wires when connecting them to the amplifier, the sound will not pass through so that you cannot use the speaker to listen to music.


The article above shows all the details you need when testing if the speaker wires are positive since it is not good to mix up speaker wires as your speaker will produce no volume. Follow the steps carefully to know what you need to do with the process. Ensure you fix back everything according to the steps of removing them in reverse.

Remember to have all the tools for the process of testing the polarity. Choose a multimeter that is best for you to read and record the values. The process of testing for polarity helps the user check for other problems and fix them by replacing the faulty parts.

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