Quick Answer:


To test a refrigerator capacitor, first safely discharge the capacitor to eliminate any stored power. Then, use a multimeter set to the capacitance measurement mode and connect the multimeter probes to the capacitor’s terminals. This process will help you determine if the capacitor is functioning properly or needs replacement.


In the intricate world of kitchen appliances, the refrigerator stands as a silent sentinel, guarding the freshness and longevity of our food. At the core of this essential appliance’s functionality is a relatively small but critical component: the capacitor. This electrical marvel plays a pivotal role in jump-starting the compressor motor, the powerhouse behind the cooling system that keeps your food fresh. However, like all components, capacitors are not immune to wear and tear or eventual failure. Recognizing the signs of a failing capacitor and knowing how to test a refrigerator capacitor can be the difference between a minor maintenance task and a costly repair or replacement.

Capacitors are designed to store and release electrical energy, providing a surge of power to the compressor motor when your refrigerator starts up. Without a properly functioning capacitor, your refrigerator may struggle to maintain the correct temperature, or worse, fail to start at all. This article delves into the critical task of testing a refrigerator capacitor, offering a comprehensive guide that ensures your appliance continues to operate efficiently. Whether you’re a DIY enthusiast looking to tackle refrigerator maintenance or simply someone keen to understand more about how your appliance works, mastering how to test a fridge capacitor is an invaluable skill that can save time, money, and prevent the inconvenience of unexpected breakdowns. Join us as we explore the step-by-step process of capacitor testing, ensuring your refrigerator remains in peak condition and your food stays safely chilled.

Understanding Capacitors in Refrigerators

Within the complex ecosystem of a refrigerator’s electrical system, capacitors stand out as critical components for ensuring the seamless operation of the appliance. To fully appreciate the importance of testing a refrigerator capacitor, it’s essential to delve deeper into the types of capacitors used and their specific roles in refrigerator functionality.

The Start Capacitor: The Initial Spark

The start capacitor plays a pivotal role in the refrigerator’s startup sequence. This component is designed to hold and then release a large burst of energy quickly, providing the compressor motor with the necessary power surge to start up. This initial boost is crucial, especially since the compressor is the heart of the refrigerator, responsible for circulating refrigerant and maintaining the desired temperature inside the unit. Without a functioning start capacitor, the compressor might not start at all, leading to a refrigerator that fails to cool.

The Run Capacitor: Sustaining Efficiency

Once the compressor motor has started, the run capacitor comes into play. Unlike the start capacitor, which discharges quickly at startup, the run capacitor releases its stored energy more gradually. This continuous supply of power helps the compressor motor run more efficiently and stably, reducing the electrical load and wear on the motor over time. By smoothing out the power supply, the run capacitor ensures that the refrigerator operates quietly and efficiently, maintaining the optimal temperature with minimal energy consumption.

The Impact of Capacitor Failure

The failure of either the start or run capacitor can have significant repercussions for your refrigerator. A faulty start capacitor can result in a compressor that struggles to start, characterized by humming noises or, in worse cases, complete failure to turn on. On the other hand, a malfunctioning run capacitor may lead to a compressor that overheats, runs inefficiently, or cycles on and off more frequently than normal. Both scenarios can lead to a refrigerator that fails to keep food at the proper temperature, potentially spoiling food and leading to higher energy bills due to decreased efficiency.

Understanding the critical roles of start and run capacitors in refrigerators highlights the importance of regular maintenance checks and timely testing. By ensuring these capacitors are functioning properly, you can prevent unexpected breakdowns, extend the lifespan of your refrigerator, and maintain its efficiency. This deeper insight into the function and significance of refrigerator capacitors sets the stage for mastering the process of testing and troubleshooting these essential components, ensuring your appliance remains a reliable guardian of your food’s fressness.

Safety First

Before testing a capacitor, ensure the refrigerator is unplugged from the power supply to avoid any electrical hazards. Capacitors can store a charge even when the power is off, so it’s crucial to safely discharge any stored energy to prevent shocks. You can discharge a capacitor by placing a resistor across the capacitor’s terminals for a few seconds.

Tools Needed

  • Digital Multimeter or Analog Multimeter: Essential for measuring the electrical resistance (ohms) and capacitance.
  • Capacitor Tester: Specifically designed for testing capacitors, but not necessary if you have a multimeter with capacitance measurement capability.
  • Insulated Gloves: For safety while handling electrical components.

Testing Your Refrigerator’s Capacitor

Testing the capacitor of your refrigerator is a critical maintenance task that can prevent potential malfunctions and ensure the longevity and efficiency of your appliance. Here’s an expanded walkthrough to help you navigate through each step with greater clarity and confidence.

1. Locate and Remove the Capacitor

The first step in testing your refrigerator’s capacitor is to locate it. Typically, you’ll find the capacitor either attached directly to the refrigerator’s compressor or mounted on the chassis. These capacitors are usually cylindrical in shape and may have two or more terminals on top. It’s important to note the capacitor’s model number and its printed capacitance value (usually in microfarads – µF) for later reference. Gently disconnect the capacitor leads from the terminals, taking care to remember the configuration for reconnection later. This might be a good time to take a photo with your phone for easy reference.

2. Discharge the Capacitor

Capacitors store electrical energy, even when the refrigerator is unplugged. To safely discharge this energy and avoid a potential shock, use a resistor (a 20,000-ohm, 2-watt resistor works well for most applications) and connect it across the capacitor’s terminals for a few seconds. This step is crucial for both your safety and the accuracy of your testing.

3. Set Your Multimeter

Prepare your multimeter for testing by setting it to the correct measurement mode. If you’re using a digital multimeter capable of measuring capacitance, select the capacitance mode. For analog multimeters or those without a capacitance function, set it to measure resistance (ohms). This preparation ensures that you’re ready to accurately assess the capacitor’s health.

4. Test for Continuity and Resistance

  • Continuity Test: Begin by checking for continuity. Switch your multimeter to its continuity setting and touch one probe to each of the capacitor’s terminals. A healthy capacitor should not complete the circuit; thus, the multimeter should not beep. If it does, indicating continuity, the capacitor might be shorted and requires replacement.
  • Resistance Test: Next, adjust your multimeter to the highest resistance range. Attach the red probe to the positive terminal and the black probe to the negative terminal of the capacitor. Observe the multimeter’s display; a functioning capacitor will show an initial low resistance, which should gradually increase towards infinity (or open circuit) as the capacitor charges. This behavior is normal and indicates that the capacitor can store and release charge as intended. A constant zero ohms reading, a very low resistance that doesn’t change, or an immediate infinite resistance suggests the capacitor is defective.

5. Measure the Capacitance

Now, it’s time to measure the actual capacitance. Switch your multimeter to capacitance mode and connect its probes to the capacitor’s terminals. The polarity of the probes is not important for this test. Compare the multimeter’s reading with the capacitor’s printed value. A good capacitor’s measured capacitance should fall within the manufacturer’s specified range. A significant deviation from this range indicates a malfunctioning capacitor that likely needs replacement.

6. Interpret the Results

  • Good Capacitors: These will initially show low resistance, which gradually increases to infinity, and their measured capacitance will align with the printed value. This indicates the capacitor is in good condition and functioning as expected.
  • Faulty Capacitors: Faulty units may exhibit constant low resistance, immediate high resistance, or a capacitance value significantly off from the expected range. Such capacitors are not performing correctly and should be replaced to ensure the refrigerator operates efficiently.

By following these detailed steps, you can accurately determine the health of your refrigerator’s capacitor. This proactive approach to appliance maintenance can save you from future inconveniences, ensuring that your refrigerator remains in optimal working condition.


The task of testing a refrigerator capacitor, while seemingly daunting at first glance, is indeed a straightforward and manageable process that requires just a handful of tools and adherence to safety protocols. The detailed steps provided above serve as a comprehensive guide, empowering even those with minimal technical expertise to assess the health of their refrigerator’s capacitor confidently. This diagnostic capability is not just about troubleshooting; it’s a proactive measure for maintaining the heart of your kitchen.

Understanding the condition of your refrigerator’s capacitor is crucial for several reasons. Firstly, it ensures that one of the most vital components of your refrigerator—the compressor—is able to start and run efficiently, directly impacting the appliance’s ability to keep your food at the right temperature. A failing capacitor can lead to inconsistent cooling, spoilage of food, and increased energy consumption, all of which are inconvenient and costly.

Moreover, regular testing and maintenance of appliance capacitors underscore the importance of preventative care. By identifying potential issues early, you can avoid the unexpected breakdowns that lead to emergency repairs or, in the worst-case scenario, the need for a complete appliance replacement. Such preventative measures not only save time and money but also extend the lifespan of your refrigerator, making it a reliable fixture in your home for years to come.

Additionally, this practice of regular maintenance contributes to the overall safety and efficiency of your household appliances. A well-functioning capacitor ensures that the refrigerator operates within its designed parameters, reducing the risk of overheating or electrical issues that could pose a danger to your home and family.

In conclusion, the ability to test a refrigerator capacitor is an invaluable skill that goes beyond mere troubleshooting. It’s about ensuring the reliability, efficiency, and safety of an appliance that plays a critical role in our daily lives. By following the guidelines outlined in this article, you can take a significant step towards safeguarding your food’s freshness and your family’s well-being, all while optimizing the performance and longevity of your refrigerator. Remember, a little knowledge and preventative maintenance can go a long way in keeping your kitchen running smoothly.

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