How to Test Car Stereo with a Multimeter?

How to Test Car Stereo with Multimeter - Featured image

To test your car stereo using a multimeter, you need to have a 12 volts source that has a minimum of 1 amp. First, check the diagrams of the wires to get the correct detail. Note that the power wire colors are universal; hence they don’t vary with manufacturer. When connected, begin taking the readings for the stereo from the multimeter.

If you don’t already have a multimeter, the AstroAI Digital Multimeter is a top-rated product and one we’d recommend.

How to Test Car Stereo with Multimeter

Before checking your car stereo using a multimeter, you should have basic knowledge of how they work.

The average digital multimeter gets fitted with two lead types. The leads are black and red.

The red lead gets connected to the voltage, current, or resistance and gets referred to as the positive terminal.

The black lead gets connected to the ground or common port and is the negative connection. A multimeter comes with a probe that gets used to holding the connections tested.

  • Testing voltage

To test the voltage of your car stereo, disconnect the end of the harness feeding the radio.

When this gets done, set the multimeter switch to Direct Current and set the multimeter to the intended range of the function. This range should be between 11 and 16 volts, Direct Current.

Touch the negative lead to the bare metal on the car.

Next is to link the positive lead with the wires in the harness, which needs testing. Finally, ensure the car is in the ACC position with your key. At this point, look at the reading indicated on your meter, and it should show a value between 11 and 16 volts.

  • Continuity testing

Ensure that the wire to the harness feeding the radio gets disconnected. Also, ensure both ends of the harness you want to test get disconnected.

The switch should get turned to the resistance mode on your multimeter. You will identify the setting via an image of an arrow that points towards the positive.

A multimeter showing how to test car wiring with multimeter

  • Radio antenna testing

The antenna of your radio helps you receive signals. It does this by generating an impulse that navigates through a conductive wire straight to your radio.

You can test with ease if the signal is moving via the antenna to the radio using a multimeter. Signal disruptions occur when there is a short in the circuit.

Also, in a case where the radio antenna is not well grounded, there may be electrical potential interference from the antenna itself. Antenna circuit resistance gets measured using the Ohms setting of the multimeter.

When testing for the signal on the car, ensure to unplug the antenna cable that is behind the radio. Touch one of the leads of the multimeter with the antenna’s metal part and touch the other lead to the cable’s metalcore.

You should have zero ohms reading. If you observe a resistance greater than this, it means your radio antenna is faulty.

Analog & Digital Multimeter Testing: How to Test a Car Stereo with A Multimeter

Multimeter sketch

How to Test your Car Stereo Using a Digital Multimeter

At the front panel of the digital multimeter, you will find a screen displaying readings.

You will also find the main switch that has options for measurement types such as volts, amps ohms, and so on. You will find connections for the probes, sometimes up to four connections.

One is for current measurement, while there is another for measuring resistance and voltage.

There is a connection used to measure low current ranges and another that could be used for temperature probes.

The operation of a digital multimeter, itself is straightforward. Once you know how to make voltage, current, and resistance measurements, it is a matter of putting the multimeter to use. According to Best Car Audio, If the meter is new then it will be necessary to install a battery to power it.

This is simple and straightforward, and details can get found in the operating instructions for the DMM.

Checking your car stereo using a digital multimeter is very easy. Here are some steps that should help you use it with ease:

  1. Switch on the multimeter
  2. Fix the probes into the right connections as there may be different connections available, which could be confusing
  3. Set the switch to the right measurement range and type. When you are choosing the range, make sure the highest range goes beyond what is anticipated. The range indicated on the digital multimeter may then get lowered as needed. When you choose a very high range, it will prevent the multimeter from getting overworked.
  4. Ensure to optimize the range to get the ideal reading. You should set the leading digits not to read zero, by doing this, only the greatest number of digits with significance will get read.

AstroAI Digital Multimeter

How to Test your Car Radio using an Analog Multimeter

Here are a few steps to follow to test your car stereo using an analog multimeter:

  1. Fix the probes into the right connections as different connections could get used. Do not put the probes into connections with low current especially if you intend to carry out a high voltage measurement. Doing this could cause damage to the multimeter.
  2. Ensure the switch is set to the right measurement range and type for the measurement. When choosing the range, ensure you go for a range above what you are anticipating. You may lower the multimeter range later if the need arises. But when you choose a range that is too high, you will prevent damages to the meter.
  3. Make sure you optimize your multimeter range to get the best reading. If you can, you could alter it to ensure that the meter’s highest deflection can be gained. Doing this will ensure correct reading.


Final Thoughts

Testing your car stereo shouldn’t be difficult if you know how to use a multimeter.

If you are familiar with your radio type, you shouldn’t face too many challenges.

According to this video by Sonic Electronics you need to know the settings to use your multimeter if you want to get the most of it.

Picture of Alex
I loved my car but was frustrated with my media system. So I upgraded my stereo, making silly wires and precarious phone mounts a thing of the past. The Apple Car Play stereo was so good I wanted to show more people how this could be done and truly upgrade their cars multimedia system! Founder
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