Air Conditioner Fuse: Where Is It & How To Tell If AC Fuse Is Blown?

Air conditioners are not something that breaks easily. As a result, most of us don’t know much about the components inside, even if we have owned them for years.

For example, many people have heard about air conditioner fuse and know it can provide some kind of protection for the machine, but don’t know where it is and how to tell whether or not it is blown.

If you have any questions about the air conditioner fuse, you have come to the right place. I will answer all the common questions about it so that you will have a firm understanding of this crucial part of your AC. No technical background is required!

What is an air conditioner fuse?

what is ac fuse

Similar to any fuse in electrical appliances, an air conditioner fuse is a failsafe that can protect your air conditioner from receiving too much power.

As you know, when an air conditioner is exposed to high amperage, it will run the risk of catching fire and breaking down. With the help of this little gadget, you can avoid a lot of these potential dangers.

An AC fuse is a small glass tube with a metal wire inside. The metal wire can transfer current to other parts of your AC. However, when too much current passes through it, the metal wire will be blown, and the power will be cut off.

Where is the fuse on my air conditioner?

Although many people know their air conditioners come with fuses, they don’t know where they are. In fact, the locations vary depending on the types of air conditioners.

Fuse location in central AC

Many central air systems have two fuses. One is in the disconnect box near the outdoor unit, and the other is located in the electrical panel of the indoor air handler. 

This way, the outdoor and indoor units can be protected separately.

Fuse location in split AC

split ac fuse location

Unlike central air conditioners, the fuse of a split AC is harder to access because it is located on the electrical panel, which is on the right side of the indoor unit beside the air filter.

If you want to check it, you should first open the front panel and then remove the air filter. The fuse is smaller than the one you will find in the central AC.

As for the outdoor unit, it has other types of overcurrent protection devices to prevent any hazards.

Fuse location in window AC

Not every window air conditioner has a fuse. If it is available, you can often find them in the electrical panel, which is behind the right side of the front panel.

If you still can’t locate the fuse, you can refer to the manual or call the manufacturer. 

How to tell if an AC fuse is blown?

As pointed out above, AC fuses protect an air conditioner by blowing the metal wire. But how do you know if the AC fuse is blown exactly, there are some useful tips.

Use a multimeter

This is the most straightforward and accurate way to know if the fuse is blown. But you should cut off the power supply beforehand. By attaching two leads of the multimeter onto the lugs of the fuse, you will know if there is any current passing through the fuse. 

If the reading doesn’t show up or you can hear a beeping noise, it often indicates that the fuse is blown.

This video from How2.101 will show you how to test it step by step.

Your air conditioner stops working

Since the blown fuse will stop the current from going through, the indoor or outdoor unit will stop working immediately. Thus, once you notice your ac stops producing cooler air, it is likely that the fuse is blown.

Strange noises

Before the fuse is completely blown, a short circuit or power surge may happen. Therefore, you can often hear some buzzing or humming noise. 

Burning smell 

Along with the noise, your AC may emit some burning smell due to some parts becoming overheating when receiving too much power.

How to replace AC fuses?

If air conditioner fuses are blown, you should replace them other than repair them. If possible, you should leave it to a professional if you don’t have the expertise. However, for those who insist on doing it yourself, you can use the steps in this section as a reference. 

1. Shut down the breaker to prevent electric shocks. 

2. Wear a pair of rubber gloves if possible and ensure the hands and feet are dry.

3. Locate the blown fuse and take a picture so that you can easily understand what the right placement of the wiring and fuse is.

4. Pull the bad fuse out. 

5. Install the new fuse and then put everything back.


We often feel lost when we encounter electrical issues in an air conditioner. When an air conditioner stop working, people often suggest we check the fuse.

In fact, air conditioner fuse is a safety feature that can protect your air conditioner by cutting off the current. It is often located in the disconnect box or electrical panel.

Hopefully, this post has helped you to understand the fundamentals of the air conditioner fuse. If you don’t have the expertise, you shouldn’t replace the fuse on your own.

About The Author

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested dozens of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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