How to Check Windings On a Motor? Here are The Best Methods

An electric motor’s elements can become defective over time. So, it is necessary to check the motor’s windings from time to time. Because checking motor windings helps to detect faulty wires, defective coils, bearing issues, etc. There are many ways you can test the faulty part of a motor. So, how to check windings on a motor?

You can check windings on a motor in various ways. You can use the resistance measurement method to test the winding. Moreover, using a multimeter and voltmeter will also help to find out the faulty component. 

Further, I will talk about how to test a motor winding, how to test an electric motor with a multimeter and voltmeter, how to test a three-phase induction motor, and many more. Please read till the end to find out!

How to Check Windings On a Motor?

There are multiple methods for testing electric motor windings. But, some are the best ways to detect a fault better than other testing methods. However, here I have discussed some ways you can check and test electric motor windings, and how do you control the speed of a DC motor. Please check it out below:

You can find out the faulty part in the winding by dividing the voltage with the motor’s current. Higher motor winding resistance leads to low power efficiency. 

It leads the motor to get damaged due to power loss. However, you can find out the resistance of the winding through Ohm’s law. Here is what Ohm said about the resistance –

Ohm’s law – The resistance is equal to the voltage divided by the current. 

So, you need to test the voltage and current to check if the motor parts are working correctly or not. Further, I will discuss the step-by-step guide on different methods regarding the checking of windings through resistance! 

How To Tell If An Electric Motor Is Bad?

The bearing and shaft of the winding must perform optimally to ensure the electric motor’s best performance. You can start the DC motor by rotating the shaft. If you notice that it is making sounds, then the bearing has gone bad. If the problem is not too bad, it can be fixed by lubricating oil. 

However, if the bearing has become defective completely, you need to replace the whole bearing. In that case, taking the help of a professional will ensure the safe replacement of your electric motor’s bearing. The electric motor has to work efficiently to run any application. 

So, here I have added some more signs that will help you to discover the problem beforehand. When an electric motor goes bad, you can find out by checking the symptoms. Please go through the points below to learn about the signs:

  • The motor would make rattling, grinding, and humming noises. It most likely hints about a bad bearing.
  • The motor would get overheated. You would notice it being over the temperature often. It’s a sign that the fan of the motor is dirty and unclean.
  • The fuses of the motor will blow out frequently. It indicates a problem in the circuit.
  • The motor will work improperly. You could notice the changes in the motor’s operation such as problems with the motor stopping and starting.

How to Test an Electric Motor with A Multimeter?

A multimeter is used to check the voltage, current, and resistance of a motor. A Multimeter helps to measure the resistance of the windings. It also helps to know the measure of voltage and current. You can test an electric motor’s resistance by using the multimeter. It makes the process easier. Please go through the below points to learn about it: 

  • Turn off the motor 
  • Locate the winding of the motor
  • Start the multimeter after choosing the terminal 
  • Connect the meter’s wiring with the terminal 
  • Now notice the resistance of the motor. If the resistance matches with manufacturer’s given value, then the wire is working perfectly
  • Use Ohm’s law to check if the resistance is high or low. You can divide 2 amps of current with 8 volts of voltage. The resistance should be lower to ensure the motor is working fine
  • Finally, you’re done

How to Check Motor Winding with Megger?

You can test the electric motor using a Megger. It is also an electric device that helps to measure the flow of current. Follow the steps below to learn how to use a Megger to check electric motor windings: 

  • Disconnect the motor from the power terminals 
  • Connect the positive terminal of the Megger to the motor’s winding
  • Connect the negative terminal to the motor’s ground
  • Now apply the test voltage 
  • Compare the result with the manufacturer’s resistance range. If it’s within the manufacturer’s range, then the motor winding is working well. If it’s not within the range, then the motor has problems with the winding

What to Know When You Check A DC Motor?

You should be aware of the precautions when you check and inspect the DC motor. Being un-careful about such a situation can lead you and your DC motor to potential harm. Please go through the precautions you must take before you check a DC motor: 

  • You should not leave a short-circuited battery without attention for a long period as it may explode.
  • If you have a single-phase induction motor, then you should avoid operating the machine beyond 12V.
  • Always wear goggles to avoid any harm to your eyes.
  • Wear safety gear to protect yourself from potential harm.
  • Replace defective parts only if you know how to do it correctly. Otherwise, you must take the help of a professional mechanic.

How To Test A Three-Phase Motor With A Multimeter?

Usually, the process for testing the single-phase motor and three-phase motor is different. If you are going to test it with a multimeter, then you need to follow some steps to ensure the overall health of the electric motor. Please check out how you can test the electric motor through below points: 

Step 1: Measurement and Winding Test 

  • Take note of the applied voltage and current. If it is the same as the resistance of the manufacturer, then the circuit is working properly
  • Now check if the winding’s phase is working correctly or not through the multimeter 
  • The three-phase of the winding should give equal reading if the circuit is working well 
  • Use insulation to check the circuit. You can do it by placing a high DC voltage. It will help you to detect any fault in the circuit easily. 

Step 2: Load Test

  • Run the motor without load. Then check the current and voltage of the circuit. If it’s within the rated voltage, then the circuit is working perfectly. In that case, you don’t need to change the DC motor direction.
  • Run the motor with the load. If the current is less than 10% of the rated load and the voltage is within the range, then the circuit condition is good.

Step 3: Final Test 

  • Now use a thermometer to check the motor’s temperature. It will help you to know if the motor is overheated or not. 
  • You can also inspect if there is any vibration in the mechanical components.
  • Finally, if you find defective parts in the machine, you have to replace or repair those components.

If you leave any problem as it is without attention, then it will lead to a bigger problem and ruin the motor completely. Hence, you should take action as soon as possible.

How to Replace Electric Motor Bearings? 

Electric motor bearings are a crucial part of running the motor. If it goes bad, it can be repaired. But sometimes repairing cannot help. You must replace the bearing completely to ensure the motor works properly. You can replace the electric motor bearings by following the below steps: 

Step 1: Make a marker on both ends of the motor.

Step 2: Remove the bolts of the motor.

 Step 3: Spray at the end of the motor. 

Step 4: Remove the rotor to get access to the bearing. 

Step 5: Now take a puller and remove the bearing of the motor.

Step 6: Now Install the new bearing in the electric motor.

Step 7: Put back the rotor in its place. Secure the motor with bolts.

Step 8: Finally, you’re done!

How to Rewind an Electric Motor? 

If the winding of the electric motor has gone bad, then you can remove the old winding. Therefore, you can rewind the electric motor. Please follow the steps below to rewind an electric motor: 

Step 1: Clean the area before rewinding the motor. 

Step 2: Remove the bolts and screws of an electric motor to get access to the internal components. 

Step 3: Take out the armature from the stator.

Step 4: Now open the tabs of the motor with a screwdriver. 

Step 5: Now cut the electric windings of the motor. 

Step 6: Install new windings. The windings should have the same number of windings that you removed earlier.

Step 7: Reassemble the motor as it was before. 

Step 8: The windings have been changed successfully.

Frequently Asked Questions

People have frequently asked questions regarding the windings on a motor. You may have similar queries. So here I have answered some questions. Please check it out below:

Q. How to Know If Motor Winding Is Burnt? 

You can get to know if motor windings are generating overheating. The winding will turn black leaving spots on it. So you will get to know that the motor winding is burning.

Q. How to Clean Electric Motor Windings?

You can use a washing chemical to clean the electric motor windings. Then the windings should be dried at 250 degrees Fahrenheit for a few hours. Finally, the electric motor windings will be cleaned.

Q. Why Does Motor Windings Failure Happen? 

A motor winding failure happens due to the breakdown of the winding’s insulation. It happens when the winding has contaminants, vibration, and abrasion. Overvoltage is also an issue for motor winding failure. 


It is crucial to check the mechanical components of a machine to extend its life expectancy. So, checking the motor winding will help you to detect failure in any part. It will protect your machine from potential damage. So, checking the components beforehand and replacing them as soon as possible is needed. 

Here, I have discussed how you can check the winding by using winding resistance measurement. If any part has gone defective, you can always get professional help. So, I hope you learned how to check windings on a motor through this article. 

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