How to Tell if Your AC Fuse is Blown

We’re not talking about your home’s fuse; you probably know how to check if that one has blown. But did you know there is another fuse inside your air conditioner itself? If the AC has turned off or if it seems to be behaving unusually, it could be that this fuse has blown. Here is how to tell if your AC fuse has blown, along with some other useful information.

Signs Your AC Fuse is Blown

The AC fuse is a safety mechanism there to turn the machine off if there is an electrical overload. Without the fuse, your air conditioner could be damaged by the current and you could end up needing to replace the whole unit. Because the fuse has blown, the air conditioner is protected.

If your AC fuse is blown, it’s most likely that your air conditioner will stop functioning entirely. Or, it will keep the blower running, but every other component will stop working. Of course, there could be other problems that make your AC stop working. So, how do you tell for sure whether your AC fuse is blown?

Test Your Fuse with a Multimeter

If you have a digital multimeter, then you can test the AC fuse directly. Here’s how:

Step One: Ensure your multimeter is working. Test it by touching both ends together. It should beep or otherwise indicate the circuit is complete.
Step Two: Locate the AC fuse. You can find it on the unit’s control board. Open up the lower panel on the air conditioner and find the labelled switch.
Step Three: Find the AC’s probes or connection points and place the multimeter on them. If you do not feel comfortable finding the probes or do not know how to, please don’t attempt this. Electricity can be dangerous.
Step Four: Either the multimeter will beep and display a measurement of the circuit, or it will not. If it does make a sound, then the AC fuse isn’t blown, and the circuit is complete. If it does not make a noise, then the fuse is blown.

What if you don’t have a multimeter? Sometimes looking at the fuse can help. If the window of the fuse is obscured, or if there is a flash mark, then it is likely the fuse has blown.

So How Do I Fix the Fuse?

Well, unfortunately, it’s not that simple. A blown fuse usually indicates that something else is going on with your air conditioner. It’s important to figure out what that is and fix it before you deal with the fuse, or it is just going to blow again. Remember that a fuse is a safety feature and running the air conditioner without solving the safety issue is not a good idea.

There are several issues that could cause a blown fuse in your air conditioner, including: