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How to Test RV AC Capacitor: A Comprehensive Guide

Are you experiencing issues with your RV’s air conditioning (AC) system?

One potential culprit could be a faulty capacitor.

The capacitor plays a crucial role in the AC unit’s operation, and a malfunctioning capacitor can lead to reduced cooling performance or even complete system failure.

In this article, we will guide you through the process of testing an RV AC capacitor to determine if it needs replacement.

By following these steps, you can diagnose the issue accurately and save on costly repairs.

So, let’s dive in and learn how to test an RV AC capacitor effectively!

How to Test RV AC Capacitor

Here, we will outline a step-by-step process to help you test the RV AC capacitor and determine its functionality.

Step 1: Safety First

Before we begin, ensure your safety by taking the necessary precautions.

Switch off the power supply to the AC unit and disconnect it from the power source.

It’s crucial to avoid any electrical accidents during the testing process.

Step 2: Gather Required Tools

To test the RV AC capacitor, you’ll need a few tools and equipment.

Here’s a list of what you’ll need:

  1. Multimeter: This device measures electrical values like voltage, resistance, and capacitance.
  2. Insulated gloves and safety goggles: Protect yourself from any potential electrical hazards.
  3. Screwdriver: Required for accessing the capacitor in the AC unit.

Step 3: Locate the Capacitor

The AC capacitor is typically located in the RV’s AC unit.

You may need to remove the unit’s outer cover or access panel to locate it.

Refer to your AC unit’s manual or consult a professional if you’re unsure.

Step 4: Discharge the Capacitor

Before testing the capacitor, it’s crucial to discharge any residual charge.

Failure to do so could result in electrical shocks.

Use a screwdriver with an insulated handle to bridge the terminals of the capacitor.

Take caution while performing this step.

Step 5: Test Capacitor’s Resistance

Using a multimeter set to the resistance mode, proceed to test the resistance of the RV AC capacitor.

Follow these steps:

  1. Attach the multimeter’s probes to the terminals of the capacitor.
  2. Observe the resistance reading on the multimeter’s display.
  3. Compare the reading to the manufacturer’s specifications. A significant deviation from the specified range indicates a faulty capacitor.

Step 6: Test Capacitor’s Capacitance

Apart from resistance, it’s crucial to test the capacitance of the RV AC capacitor.

Follow these steps:

  1. Set the multimeter to the capacitance mode.
  2. Connect the multimeter’s probes to the corresponding terminals of the capacitor.
  3. Read and record the displayed capacitance value.
  4. Compare the reading to the manufacturer’s specified range. If it falls outside the range, the capacitor may be faulty.

Step 7: Analyze the Results

Based on the resistance and capacitance readings, you can assess the RV AC capacitor’s condition:

  • If both readings fall within the manufacturer’s specified range, the capacitor is likely functioning correctly.
  • If the resistance reading is significantly high or infinite, the capacitor may be open or disconnected.
  • If the capacitance reading is significantly low or zero, the capacitor may be shorted.

Frequently Asked Questions (FAQs)

Can I test an RV AC capacitor without a multimeter?

While a multimeter is the most reliable tool for testing an RV AC capacitor, you can also visually inspect it for any visible signs of damage, such as bulging or leaking. However, this method is less accurate and may not provide conclusive results.

How often should I test my RV AC capacitor?

Regularly testing your RV AC capacitor is not necessary unless you notice a decline in the cooling performance of your AC system. However, it’s good practice to include capacitor testing as part of routine maintenance.

What if my RV AC capacitor fails the test?

If your RV AC capacitor fails the resistance or capacitance test, it is recommended to replace it with a new one. Faulty capacitors can lead to AC system malfunctions, reduced efficiency, and increased energy consumption.

Can I replace the RV AC capacitor myself?

Replacing an RV AC capacitor can be a DIY task if you have the necessary knowledge and experience. However, if you’re unsure or uncomfortable with electrical work, it’s best to seek professional assistance to ensure the job is done correctly and safely.

Are there any safety risks associated with testing an RV AC capacitor?

Yes, there are safety risks involved when working with electrical components. Always follow safety precautions, such as wearing insulated gloves and safety goggles, and ensure the power supply is switched off and disconnected before testing or replacing any capacitor.

Is it possible to repair a faulty RV AC capacitor?

Generally, capacitors cannot be repaired. Once they malfunction, it is best to replace them with new ones. Attempting to repair a faulty capacitor can be dangerous and may not yield reliable results.


Testing an RV AC capacitor is a crucial step in diagnosing AC system issues.

By following the step-by-step process outlined in this guide, you can effectively determine the functionality of the capacitor.

Remember to prioritize safety during the testing process and consult a professional if you’re unsure or uncomfortable with electrical work.

Regular maintenance and timely replacement of faulty capacitors will help keep your RV’s AC system running smoothly, ensuring optimal comfort during your travels.