How to Test a Washing Machine Motor with a Multimeter

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How to Test a Washing Machine Motor with a Multimeter

Your washing machine’s motor helps to run its drum and pump; It’s the engine of your washing machine. If the motor fails, your machine can’t work. The chances of motors failing aren’t high, especially with modern technological advancements helping improve quality.

The motor used in your washing machine – if you own a modern one – is designed and constructed ruggedly. Under perfect conditions, these motors should be properly functional and last the lifetime of your washing machine. All you need is to conduct proper preventative maintenance.

Unfortunately, there are times when a washing machine motor can start showing problems such as having failed starts, running hot, running intermittently, continually tripping overcurrent devices, and making strange noises when in operation.

These are signs that you need to test your washing machine. However, if your washing machine stops working, there may be other culprits. To make sure that your motor is the faulty culprit, you need to carry out tests on its circuits. The tests will enable you to identify the problem and perform routine maintenance on your washing machine.

Testing your washing machine’s motor is a procedure that almost anyone can do with a little knowledge and a few tools mostly found in most home’s tool kits. One such tool is a digital multimeter: an affordable handheld diagnostic tool for taking various electrical readings. A digital one is better than an analog multimeter and gives more accurate results. Here is an in-depth guide on how to test a washing machine motor with a multimeter.

Equipment Needed for Testing a Washing Machine’s Motor

You will need the following equipment and tools for performing motor tests.

  • Insulated work gloves 
  • A digital multimeter
  • Needle-nose pliers
  • Flat-blade screwdriver

#1 Shut Off The Motor’s Power

Unplug the machine from the wall outlet or turn it off from the circuit breaker. If you aren’t sure which breaker controls the machine, it is advisable to shut off the main power supply. All these are precautionary measures to avoid the risk of electric shock; with machines, anything can happen.

Safety Tip: Since washing machines run on 240-volt (or 220 volts), never work on a motor that’s powered on.

#2 Locate The Motor: Disassemble Your Washer’s, Motor Shell.

First, locate where the motor is fitted on your unit. Alternatively, you can refer to your washing machine’s manual. Using a screwdriver, remove the rear panel to access the motor of your machine

Check if there is any dirt in the motor. Any accumulated dirt should be cleaned as sometimes is the motor’s metal contacts from closing.

#3 Disconnect The Wires.

Upon accessing your motor, two-wire leads are connected to the motor, disconnect them from the wiring harness.

You should take a picture or draw a chart of how the wires are connected, as it will help you to remember when reassembling.

Safety Tip: To remove any current that may have remained, touch your screwdriver’s blade to one terminal and the shaft to the other terminal.

#4 Setting Your Multimeter and testing the motor 

  • First, set your multimeter to the lowest setting, or RX1.Setting.
  • Take one of your multimeter probes and touch it to one terminal on the motor.
  • Take the other probe and touch it to the other terminal on the motor.
  • Check the readings on your multimeter
  • If your motor is good, it will have little resistance i.e.0 or close to zero. The reading is an indication of properly functioning motor coils
  • If the reading is a high number or it shows “infinite,” your motor is defective

Safety Tip: Always grip the rubber handles on the multimeter probes when performing these tests.

Testing Ground Connection

To check the ground connection

  • Touch one of your multimeter’s probes on the bare metal housing of your motor.
  • Touch the other probe on each terminal, each one at a time, and note the readings.
  • If your motor is fine, you shouldn’t have seen any reading apart from zero on your multimeter from this test.
  • Any reading reflected that isn’t 0 indicates that your motor isn’t grounded properly.
  • If the motor failed both tests, it’s faulty and needs replacing

Testing the Motors Capacitor

A damaged capacitor can also cause failure in a motor. That’s why we are also going to look at how to test a motor’s capacitors. As recommended above, draw a chart or take a picture of the motor to remember how they were set up during replacement.

#1 Unplug from Power Source

Similar to the above test, you should first unplug your machine from any power for safety reasons

#2 Locate and Disconnect wires from their Terminals

Find the motor’s start capacitor and remove its metal cover. It is the larger one of the two capacitors. Using your noodle-nose pliers, disconnect the two wires from the terminals.

#3 Discharge the run capacitor

To discharge the Run Capacitor, place one alligator clip from your jumper wire to the body of the capacitor. Then place the other alligator clip on the metal shaft of your flat blade screwdriver.

Now place the blade of your screwdriver on one of the motors terminal and its shaft on the other terminal. The procedure will short out the capacitor eliminating any risk of electric shock from stored charge.

#4 Set Up Your Multimeter

Set your multimeter to take ohm readings. Touch the two lead multimeter probes on each other than switch the adjusting wheel to point upward. (where it reads 0)

#5 Perform Checks on the capacitor

Touch each of your multimeter probes to the capacitor terminals. The black probe should connect to the right. The red probe should go to the left. Upon doing this, the multimeter readings needle should jump from zero to the right and then go back to 0.

Now reverse the multimeter probes with the black going to the left and the red going to the right. The reading’s needle should move from 0 then go back. If the reading needle fails to move in both procedures, the capacitor is faulty and needs to be replaced.

About the Author Dan

Just a random guy who likes to build things. Providing tool knowledge, appliance/device testing tips, and DIY project info in an easy-to read & non-intimidating style.

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