Last Updated on September 18, 2020
Today there are a lot of electrical and electronic components that need to be checked. It is useful to have test leads or some kind of multimeter. This way you can check the status of the fuse box in your home or vehicle. It is necessary to mention that fuses can deteriorate when you least expect it.
Below you can learn how to check a fuse with a multimeter. It is also necessary to look inside the fuse. In this case, learning to look inside the fuse can save you the trouble of using a multimeter to test your fuses. It will also be much easier to detect a good fuse and separate one that is blown.
So the important thing here is:
- Consider the voltage of a fuse
- Measure the number of ohms
- Checking fuses in a fuse box
- Measuring resistance if a fuse is blown
- Check the current state of the circuits
How Do You Check if a Fuse is Blown with a Multimeter?
In this case, checking whether a fuse is blown using sight only may not be sufficient. So it is very useful to use a multimeter and get rid of all the doubts. So, here the objective is to perform an electrical test and test what has happened with a fuse.
First of all, you must have the continuity mode in your multimeter. Most of the best multimeter now have this mode of use. Then, one of the probes must be placed at one end of the fuse. Of course, the other probe of your multimeter must also be placed at the other end of the same fuse.
Here the main objective is to detect whether the fuse is in good condition or not. So, in continuous mode, the multimeter should beep to indicate that there is continuity. If you can test that there is continuity then the fuse is not blown. In other words, it means that no connection is damaged or broken.
On the contrary, it could be that the multimeter indicates a high level of resistance without making a sound. So, when this happens, the main reason is that the fuse is already blown and therefore not useful.
Additionally, you can also use the ohmmeter of a multimeter if it does not have a continuity mode. So, you must select the ohmmeter and place each waveform at each end of the fuse.
If the fuse is not damaged, then the ohmmeter reading should below. Conversely, if the fuse is damaged or blown then the reading will be very high.
How Do You Check if a Fuse is Bad?
Here, checking if a fuse is good will allow you to save a lot of common contingencies. However, a good fuse is not always available so you should learn how to test the status of a fuse. You can use a multimeter or simply detect at a glance if a fuse is completely blown.
Checking a fuse with a multimeter is always useful although there are other ways. Here you should make sure of the main aspect that a fuse counts. It is not very difficult to detect a blown fuse. Sometimes the main connector of the fuse is melted or simply broken.
If you can’t make sure of this, you can continue to use a multimeter. Usually, when a blown fuse has a broken connector, there is nothing left to do. Conversely, a fuse is fine if the internal connector is not melted in any of its parts. This connector must be completely in condition from one side to the other of the fuse.
Additionally, you must have a new fuse to replace the blown fuse. Of course, there are a lot of fuses available on the market. So, you should also make sure that the new fuse is the same type as the old one. In case you can’t make sure of that, you won’t be able to get the same functionality as before.
How Do You Test a Fuse and Relay with a Multimeter?
Especially to be able to test a fuse with a multimeter you must use the continuity mode on your multimeter. Then you must connect each of the multimeter probes to each end of the fuse. If you can detect continuity on your multimeter, then it means the fuse is good. Conversely, if you don’t detect continuity in your multimeter, then it’s a blown fuse.
On the other hand, you can test whether a coil relay is in good condition or just not anymore. To do this, you must also have a digital multimeter with 7 functions. In this case, you will need to use the resistance mode between each pole of the relay. Here the readings must be zero ohms in the corresponding pole of all the contacts. (1)
At the same time, the contacts in that area should also be viewed as an infinite resistance reading if you locate the probes in the corresponding pole. You can then continue after energizing the relay. You will hear a clicking sound when the relay is energized.
So you will have to repeat the procedure using your multimeter. Here the resistance of the NC and NO contacts must be adequate. You can also test the solid-state relays with your multimeter. (2)
In this case, you need to have the diode reading to test this type of relay. The multimeter will read the voltage applied to the relay. When a relay is not working, then the meter will read zero or OL. Conversely, a relay that is in good condition should give a result of 0.5 or 0.7 depending on the type of relay.
To extend the life of a given relay, you must keep them cold for as long as necessary. In this way, you will be able to extend the life of these components. At the same time, solid-state relays are usually cheaper and easier to fix.
After testing the fuses in your home, you will be safer from there. Checking a fuse with a multimeter is always an option. Here you can test that the circuits are in good condition. So it is important to purchase a digital multimeter, as you will probably need it to test a fuse.
In this way, all the fuses in your home will be in good condition. Also, it is a way to detect and prevent possible electrical problems in your home.
We have other HOW-TOs articles that you may want to check and bookmark for future references. Some of these are: How to Tune an Amp with a Multimeter, and How to Use a Multimeter to Test Voltage of Live Wires. We hope this learning guide helps you.
(1) coil – https://www.britannica.com/technology/coil
(2) solid-state – https://electronics.howstuffworks.com/question558.htm