How to Test and Replace a Washing Machine Tachometer

Jul 10, 2023, 16:16pm

The tachometer, also called the tachometer generator (or tachometric generator) is the module that measures the rotational speed of the engine. This part makes it possible to indicate to the system of the device the current rotation speed and to vary it according to the progress of the washing program.

This part may need to be replaced if you experience drum rotation problems, if the program suddenly stops during operation, or if an error code appears (F53 on a Miele appliance, or 3E on a Samsung washing machine, for example). example).

If this tachometer generator is faulty, it is possible that the door cannot be opened. In this case, it will be necessary to use the tab located behind the hatch, at the level of the drain pump.

The tachometer is located in a block close to the engine, where the brushes are located. Access to it requires dismantling down to the engine.

The tachometer in a washing machine is an important component that measures the motor’s rotational speed. It provides vital feedback to the machine’s control system to ensure proper functioning and accurate timing during different wash cycles. If you suspect that the tachometer is faulty or malfunctioning, it may be necessary to test and replace it. Testing the tachometer requires some electrical knowledge and the use of a multimeter, while replacing it involves careful attention and a few tools. In this guide, we will walk you through the steps to test and replace a washing machine tachometer.

How to Test and Replace a Washing Machine Tachometer

Safety Precautions

Before starting any repair work on your washing machine, it is important to prioritize safety. Always unplug the machine from the power source before attempting any repairs. Additionally, ensure you are working in a well-lit area and wear protective gloves to prevent injury. If you are unsure or uncomfortable working with electrical components, it is best to seek professional help.

Tools Required

To test and replace a washing machine tachometer, you will need the following tools:

  • Screwdriver set (Phillips or Torx, depending on your machine)
  • Multimeter
  • Towels or rags (to protect the floor and clean up any spills)

Testing the Tachometer

Follow these steps to test the tachometer in your washing machine:

Step 1: Unplug the Washing Machine

Ensure the washing machine is disconnected from the power source by unplugging it from the wall socket.

Step 2: Locate the Tachometer

The tachometer is typically located near the motor or control board of the washing machine. Refer to your washing machine’s user manual or search online for specific information about the tachometer’s location in your particular model.

Step 3: Access the Tachometer

Remove any covers or panels that obstruct access to the tachometer. This may involve removing the back panel or a portion of the machine’s casing. Take caution and follow safety guidelines while removing components to prevent damage or injury.

Step 4: Identify the Tachometer Connections

Locate the connections on the tachometer. It will usually have three wires: one for power, one for ground, and one for the tachometer signal. Refer to the wiring diagram or user manual to identify the correct wires.

Step 5: Set the Multimeter

Set your multimeter to measure AC voltage. The tachometer signal wire will output an AC voltage, which the multimeter will measure.

Step 6: Test the Tachometer

With the multimeter connected to the tachometer signal wire, rotate the drum or start a wash cycle. Observe the multimeter reading. It should display a voltage that fluctuates with the motor’s speed. If the multimeter doesn’t show any voltage or displays a constant value regardless of the motor’s speed, it indicates a faulty tachometer.

Replacing the Tachometer

Follow these steps to replace a faulty tachometer in your washing machine:

Step 1: Unplug the Washing Machine

Ensure the washing machine is disconnected from the power source by unplugging it from the wall socket.

Step 2: Access the Tachometer

Remove any covers or panels that obstruct access to the tachometer, following the same steps as in the testing process.

Step 3: Disconnect the Tachometer

Carefully disconnect the wires connected to the tachometer. Take note of their positions or use a marker to label them for proper reconnection later.

Step 4: Remove the Old Tachometer

Using a screwdriver, remove any screws or fasteners that secure the tachometer to the washing machine. Carefully detach the tachometer from its mounting location.

Step 5: Install the New Tachometer

Take the new tachometer and position it in the mounting location, aligning it properly. Secure it in place using the appropriate screws or fasteners.

Step 6: Reconnect the Wires

Reconnect the wires to the new tachometer, ensuring they are properly positioned and securely attached. Refer to the labels or notes made during the disconnection process.

Step 7: Reassemble the Washing Machine

Once you have completed the tachometer replacement, reassemble any covers or panels you removed earlier to access the tachometer. Use the appropriate screws or fasteners to secure these components back in place.

How to Test and Replace a Washing Machine Tachometer

Step 8: Test the Machine

Plug your washing machine back into the power source. Turn it on and run a test cycle. Observe the machine’s operation, ensuring that the tachometer provides accurate feedback to the control system. Monitor the motor’s speed and listen for any unusual noises. If the machine operates correctly without any problems, it indicates that the new tachometer is properly installed.

If you encounter any persistent problems or suspect a fault with the tachometer despite the replacement, it is recommended to consult a professional appliance repair technician or contact the manufacturer for further assistance.

In conclusion, testing and replacing a washing machine tachometer is a task that requires some electrical knowledge and careful attention. By following these steps and using the appropriate tools, you can successfully diagnose a faulty tachometer and replace it to restore proper functionality to your washing machine. Always refer to your washing machine’s user manual for specific instructions and guidelines, as different models may have slight variations in the tachometer testing and replacement process. Regular maintenance and prompt tachometer replacement will help ensure the optimal performance of your washing machine.


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