how to test a compressor with a multimeter

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If you’re like most people, you probably don’t know how to test a compressor with a multimeter. But don’t worry, we’re here to help! In this blog post, we’ll show you how to easily test your compressor with a multimeter. We’ll also provide some tips on how to troubleshoot your compressor if it isn’t working properly.


Compressors are found in many household appliances, such as air conditioners, refrigerators, and HVAC systems. They work by pressurizing a fluid, which then cools or heats the area around it. In order to test whether a compressor is working properly, you will need to use a multimeter.

First, set your multimeter to the “resistance” setting. Next, locate the two wire terminals on the compressor. One of these will be marked “L1,” and the other will be marked “L2.” Touch the probes of your multimeter to these terminals. You should see a reading of around 10 Ohms on your multimeter’s display. If you do not see this reading, then the compressor is likely faulty and should be replaced.

What is a Compressor?

A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of compressor that converts power into potential energy stored in compressed air. By one of several methods, an air compressor forces more and more air into a storage tank, increasing the pressure. When paired with appropriate pneumatic tools, compressors provide numerous benefits for everything from small home projects to major industrial endeavors.

How does a Compressor Work?

The compressor is the heart of the cooling system in your fridge or air conditioner. It’s a pump that circulates refrigerant through the system. As the refrigerant evaporates, it absorbs heat from whatever it’s cooling — in a fridge, that’s the inside of the appliance; in an air conditioner, it’s the warm air inside your house. The compressor squeezes the evaporated refrigerant back into a liquid so the process can start all over again.

What is a Multimeter?

So, before we get into How to Test a Compressor With a Multimeter, let’s first understand, “What is a multimeter?” A multimeter is an electrical testing device that measures voltage, resistance, and current. It can also measure continuity, which is vital when testing compressors. You can use a multimeter to test if a compressor is working or not by checking the voltage and resistance.

How to Test a Compressor with a Multimeter

Compressors are electrical devices that compress air or other gases. They are used in a variety of applications, such as air conditioners, refrigerators, and pumps. A compressor consists of two main parts: a pump and a motor. The pump is responsible for drawing in air and compressing it. The motor powers the pump.

Testing a compressor is a relatively simple task that can be done with a multimeter. First, disconnect the power to the compressor. Next, set your multimeter to the ohms setting and touch the probes to the two terminals on the compressor. If the reading is infinite, then the windings are not damaged and the compressor is fine. If there is continuity, then the windings are damaged and the compressor needs to be replaced.

Tips and Tricks

Compressors are perhaps the most misunderstood piece of equipment in an air conditioning system. They aren’t mystery devices, they are just very simple refrigeration pumps. The main job of a compressor is to move a refrigerant through an air conditioning system. A properly operating compressor will maintain adequate pressure differences between the high and low sides of an air conditioner to allow it to cool properly. A multimeter is an instrument used to measure electrical voltage, current and resistance. It is a very useful tool for testing compressors.

When using a multimeter to test a compressor, there are a few things to keep in mind:
-Set the multimeter to the proper setting. For voltage, this will usually be “V” for volts; for current, it will be “A” for amperes; and for resistance, it will be “Ω” for ohms.
-To test voltage, set the multimeter to the “V” setting and touch the red lead (positive) to the terminal marked “H” or “HERM,” and touch the black lead (negative) to the terminal marked “C” or “COM.” This will tell you what voltage is being supplied to the compressor.
-To test current, set the multimeter to the “A” setting and touch the red lead (positive) to the terminal marked “H” or “HERM,” and touch the black lead (negative) to the terminal marked “C” or “COM.” This will tell you how much current is flowing through the compressor.
-To test resistance, set the multimeter to the “Ω” setting and touch one lead (either red or black) to one of the terminals marked “+” or “-,” and touch the other lead (black if you used red first, or red if you used black first) to one of the other terminals marked “+” or “-.” This will give you a reading of how much resistance is in the circuit.


If the multimeter reads zero or a very low resistance value, this indicates a short circuit in the compressor winding and the compressor must be replaced. If the multimeter reads infinity, this means that there is an open circuit in the winding and the compressor must also be replaced.

Further Reading

For more information on this topic, please see the following resources:

-How to Test a Compressor With a Multimeter [reference]
-How to Use a Multimeter [reference]


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