How to Test a Dishwasher Drain Pump with an Ohmmeter

Testing a dishwasher drain pump is a crucial step to ensure your appliance operates efficiently and without issues. This article will guide you through the process using an ohmmeter, providing detailed steps and safety tips for a successful diagnosis.

Tools and Preparation

Before you start, gather the necessary tools and prepare your dishwasher:

Ohmmeter or Multimeter: Ensure your device is set to the ohm setting. Screwdriver: Useful for accessing the drain pump if necessary.

Step-by-Step Procedure

1. Unplug the Dishwasher

Always prioritize safety. Ensure your dishwasher is completely powered off to avoid any electrical hazards.

2. Access the Drain Pump

The process of accessing the drain pump can vary based on your dishwasher model. Consult the user manual for specific instructions, and you may need to:

Remove the lower spray arm. Remove the cover.

3. Disconnect the Pump

Locate the electrical connector for the drain pump. Carefully disconnect it to test only the pump and not the entire circuit.

4. Set Up the Ohmmeter

Turn on your ohmmeter and set it to the resistance ohm setting.

5. Test the Pump

Place one probe on one terminal of the drain pump. Place the other probe on the other terminal. Read the resistance value displayed on the ohmmeter.

Interpretation of Results

Understanding the results is essential for determining the health of your drain pump:

Normal Resistance

A typical reading for a functioning drain pump is usually between 20 to 100 ohms. This range can vary by model, so refer to your dishwasher's specifications for the exact range.

Open Circuit

If the ohmmeter reads “OL” over limit or infinite resistance, the pump is likely faulty and needs to be replaced.

Short Circuit

If the reading is very low and close to 0 ohms, the pump may have a short circuit, indicating a failure.

Reassembly and Next Steps

After testing, reassemble any parts you removed and plug the dishwasher back in. If the pump is found to be faulty, you may need to:

Check the wires for burned-off connections. Inspect the windings for signs of overheating (blackening). Replace the faulty pump, ensuring to follow proper reassembly procedures.

Safety Tips

When dealing with electrical components:

Always ensure the appliance is unplugged before working on it. If you are unsure about any step, consult a professional or refer to the dishwasher’s service manual.

Additional Tips

For added troubleshooting, you can measure the winding resistance:

Expect some resistance, typically 4 to 6 ohms. If the reading is 0 ohms, you have a short circuit, requiring a new pump. If the reading is infinite, the circuit is likely open, and you should check the connections.

Check online for the correct model and proceed with caution when reattaching electrical components.

By following these steps, you can ensure your dishwasher operates smoothly and efficiently, prolonging the life of your appliance.