How to Check a Car Amplifier with a MultiMeter [STEPS + VIDEO]

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How to Test a Car Amplifier with a MultiMeter?

To test a car amplifier with a multimeter, configure the multimeter, locate the amplifier, and measure the power voltage. Afterward, check the fuse box and remote wires. If these are okay, you should check the speaker wires to see any signal to your speakers.

What Will You Need?

As with any other task, you need some background knowledge and tools to get started. So first of all, you will need:

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  • A Multimeter
  • Your car manual

You can get a digital multimeter at any hardware store or order it online. Do yourself a favor and get the digital one because it is much easier to operate.

The Actual Process

Don’t worry! The process might look sophisticated, but we will break it down into simple steps for you. All you need is a bit of patience, and you’re good to go.

Step 1: Setting Up the MultiMeter

You need to configure the multimeter before you can test the amplifier. For that, you need to:

  1. First, set the Multimeter to VDC mode. This mode will help you measure the direct current (DC), which you have in a car.
  2. Connect the wires. You will get two probes, red and black. Insert the black into the common (COM) socket. Similarly, you can insert the red probe into the ampere sockets. If your multimeter has two, just insert it into the socket labeled with the higher amperage. These sockets are color-coded according to the probes.
  3. There’s a dial on the multimeter. You need to turn it to the amperage settings corresponding to the socket, i.e., 20V.

Step 2: Locating The Amplifier

We know it sounds weird, but the amplifier could be anywhere with modern car designs. If you have patience and time to spare, you can search the dashboard, seats, and other places for it.
Or, you can take the easy way.

Whip out your car’s manual and see where the amplifier is in your model.

If you’re testing a aftermarket car amplifier you probabbby kow where you install it

Step 3: Check the Power

Switch the multimeter to the voltage mode. Place the probes on the power cables, positive on positive and negative on negative. If you get a zero volt reading, there’s an issue with the power.

Step 4: Check The Fuse

Your fuse may look okay, but you still need to check it with the multimeter. Put the multimeter into continuity mode and place the lead on the fuse box. If it works, you’ll hear a beep.

Step 5: Check the Remote Wire

You should see this wire between the two power wires you checked earlier. Turn on the radio, and then test this wire for voltage. If the voltage isn’t 12V, the amplifier won’t work.

Step 6: Checking Amplifier Output

If everything is okay at this point, but the sound still isn’t working, you need to check the amplifier’s output. Simply check the speaker wires. If there is voltage coming out, you should have sound. If you don’t, either your speakers are damaged, or the cables are connected to the speakers incorrectly.


This tutorial should help you diagnose the basic issues with the amplifier. You just need the patience to check each item, and before you know it, you’ll have the whole thing figured out!

Last update on 2024-07-24 / Affiliate links / *Image Disclaimer: We use images/data from Amazon Product Advertising API solely on products that link to Amazon. On products with the "Price at Crutchfield" button, we use images/data from as per the partnership deal.

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