How to Test Brushless Motor with Multimeter

How to Test Brushless Motor with Multimeter?

Have you identified any wrong issues with your brushless motor recently? Maybe it doesn’t rotate when you are trying to connect it to the main circuit. For this, first, you need to must test the motor if you desire to fix this without opening the mounting.

That’s why you need to know how to test brushless motor with Multimeter? To know about it, we need to go through this article. I will provide you with the concept so that you can effortlessly do the brushless motor testing with a multimeter.

To learn more, let’s dive into it.

Know the testing process of How to Test Brushless Motor with Multimeter

Know the testing process of How to Test Brushless Motor with Multimeter

Simply you need to follow this process:

To start, classify or align your Multimeter with the brushless motor. You fixed the Multimeter to DC because brushless motors are DC. The Multimeter needs to be aligned with the motor. And after then, use the probes to estimate the voltage, resistance, and amperage.

  • The resistance between every pair of terminals should be measured or identified(AB, AC, BC).
  • They should be of the same size. It can be conceived as a damaged or not working terminal if one pair has much greater resistance than the other one. That’s why they should be about the same size.
  • If AC = AB+BC, for example, the AC coil is damaged Open. It is a broken fall if one pair measures very little resistance.
  • While rotating the motor using a hand, then estimate or measure the AC voltage on every set of terminals.

It’s better to use an oscilloscope for this process, although you should observe some back EMF as you go ahead. An insulation resistance tester is needed to experiment with the coil insulation professionally.

Steps to follow In details



It’s the best idea to experiment and monitor the performance of a brushless motor on several bases. Give your brushless motor a thorough inspection with a multimeter, giving close attention to the instructions.

Step 1: Resistance should be checked

Switch to the Ohms test mode on your Multimeter and  Connect each and every of the two testing probes to its respective or several jacks. The black one needs to be connected to the “Com” jack, whereas the red one needs to be connected to the “Ohms” jack. You fixed the needle on the Multimeter to zero.

  • By Using the probes, collect readings on the three wires. And then Mark the wires A, B, and C with the letters A, B, and C, respectively. The experimental steps should be finished in the following order: AB, BC, and CA.
  • The readings should be limited less, which will indicate that the motor is working properly without having problems. However, if it reads 0 or any continuity, it indicates that there are problems with the motor.

Step 2: Finding out the problem

Your brushless motor’s windings can be opened or shorted. If the motor winding has been damaged or disconnected, resulting in an open winding. Insulation failure is happening by a shorted coil. You can trace out these problems using a multimeter.

  • First, check the connections or links between wires A to B, B to C, and C to A. The range limit for each of these wires must be from .3 ohms to .8 ohms on average.
  • Suppose the reading shows 0, which indicates a short between the phases if the reading shows 2000 ohms or infinite, which indicates an open winding.

Step 3:  Insulation system should be checked

Simply turn around the red probe of the Multimeter to Megaohm jack this time. You’ll have to give your motor 1000 rpm of incoming power. In order to do so, you’ll have to take the place of your motor with a higher-quality brushless motor.

  • After you’ve given the motor power, you need to double-check all three wires in the similar way you did before. The reading will limit to between 600 and 2000 Megohms. The shorts must be lesser than 20 Megohms in length.

The general rule of thumb is:  if the reading is less than 600 Megaohms, the cable may be damaged or broken.

Step 4: Checking Amperage

To start, put the red probe of your Multimeter into the “amp” Jack. The motor circuit is connected or added to a line in the Multimeter. The probe must be put into the power wire.

  • The amperage reading must be 0 at all times. If the reading fluctuates over time, there is a seriously problematic situation with your brushless motor.
  • We need to check if any components of the brushless motor are malfunctioning on several bases to avoid these internal problems.

And with that, your brushless motor has thoroughly experimented. You now understand how necessary a multimeter may be at times.

From here, we get the concept of how to test brushless motor with Multimeter.

Can a brushless motor burns out?

Excessive heat and speedy heating/cooling cycles will reason the magnet in the Rotor to vanish gradually over time (like when racing outward in the winter on a Cristal clear but cold day). The Gauss meter will need to check the Rotor’s magnetism to observe if it has faded or not.

How to experiment brushless motor without ESC?

Know the testing process of How to Test Brushless Motor with Multimeter

Brushless motors can experiment without an ESC. Firstly, Disconnect the motor from the ESC for indemnity’s sake, although it’s not necessary. Secondly, Hand-spin the rotor head by shorting any two motor wires without shorting the wires, analogy mechanical resistance. And lastly, a rep with the other two wire-shorting combinations.

How to use a multimeter for a brushless motor?

Know the testing process of How to Test Brushless Motor with Multimeter

It’s very simple to use a multimeter. You’ll need to take some readings to see if your brushless motor is working properly or not.

As we already know that brushless motors are DC motors. Therefore need to fix the Multimeter to DC mode first. Then, to the black-colored jack, connect the Common probe, also known as the “com” probe. Based on your reading, you’ll need to alternate the red probe.

A Multimeter can be used to identify the voltage, amperage, and resistance of your motor.

Balance your reading to the optimal reading numbers, and you’ll be able to find the problems on your own.

How long does a brushless motor last?


Considering a brushless motor, you desire a motor that will last a long time. But the brushed motor life is limited by the brush type and ranges from 1,000 to 3,000 hours on average, while the brushless motor can last for tens of thousands of hours.

Final Words

test brushless motor with Multimeter

Throughout this entire article, I provide the essential stuff about how to test brushless motor with Multimeter. By going through this article, anyone can examine and fix the brushless motor with Multimeter without facing any problems.

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