While still in school, you may be asked to use your multimeter for a wide range of testing and diagnostic purposes as an aspiring electrician or engineer.
A multimeter’s versatility extends beyond just measuring voltage and resistance; it’s a crucial tool for diagnosing electrical issues, like checking a fuse’s integrity. Today, we’re zeroing in on this specific function, guiding you through the process of using your multimeter to effectively assess a fuse’s condition.
Fuse testing is a basic, quick, and easy process. The first step is to measure its resistance, which indicates how well material conducts electricity and how well it dampens voltage fluctuations.
Fuses are passive components used in circuits where voltage spikes are possible. This means that an electrician has to be familiar with checking and changing fuses.
Contents
Why Test a Fuse?
A blown fuse is something that has happened to almost everyone at some point, and most of us have replaced it. However, not all fuses are inexpensive, and if you don’t have a spare on hand, you’ll need to make a trip to the hardware store or auto parts shop.
In the realm of electrical work, testing fuses is a routine yet critical task, ensuring that replacements are truly necessary. This practice, rooted in years of experience, helps in accurately identifying fuses that have blown, thereby preventing unnecessary replacements and saving resources.
Before going out of your way to buy and install a new fuse, you should check to determine if the one in question has actually blown. Fuse testing is simple, just requires a few pennies worth of equipment, and may save you time and money.
Electrical overloads can be prevented by utilizing fuses, which consist of a short length of wire housed in a particular enclosure that is designed to melt in two. We only need to check to see if that cable has completely severed.
Even though some fuses offer a small window to visually inspect the wire, the limited view and minuscule size can lead to inaccuracies. A swift, reliable 30-second multimeter test bypasses these uncertainties, providing a definitive assessment of the fuse’s status.
Why Would A Fuse Suddenly Blow?
If the circuit is subjected to more current than it can safely manage, the fuse will blow. A blown fuse indicates an electrical short between two wires or between the power line and the ground (car body).
If an element uses more power than it should, the fuse will also blow. If the wiper or blower motor is stuck and turned on, for instance, it will require more power from the outlet and may blow the fuse. If a winding within the motor is shorted, the same thing might happen. We identified many widespread issues that lead to fuse blowing:
- When a metal object (such as a penny) falls into it or when a faulty accessory is connected to the front auxiliary power socket, these are the most prevalent causes of a malfunction (cigarette lighter socket).
- When the trunk lid or liftgate is opened, the wire harness bends, causes a short circuit, and blows the fuse for the brake lights or taillights.
- It is also possible to blow a fuse by using the incorrect bulb in the car’s headlights or taillights.
- Trailer wiring that has been chafed or scraped causes an electrical short.
- The fuse in the car’s electrical system was blown because a wire harness in the engine compartment had worn through. When the insulating on the main wiring harness breaks, it can cause a short causing the fuse to blow, an issue that is frequent in some older Mercedes-Benz vehicles.
Multimeter Fuse Test
Like the continuity tester, a multimeter has two leads. A multimeter, on the other hand, can measure current, voltage, and resistance across a wide range of values. Multimeters come in a wide variety of forms, including those that are auto-ranging (no need to select a range) and those that use a needle or digital display to display the reading.
The initial step in using any multimeter is to switch the setting to resistance (). If there are many ranges to pick from, go with the lower one (K on the dial represents thousand, so 2K equals 2000). Put one probe on a continuity tester and touch it to each fuse contact.
If the meter reads 1 ohm or less, the fuse is fine; if it reads infinite, the fuse has blown. Wiggle the sensors on the fuses contact, clean them, and try again if you get an intermediate reading of several ohms.
Determine the Ohms with a Multimeter
To test the resistance, you’ll need a multimeter with resistance reading capabilities. If the fuse is open, the ohms will be quite high, but if they are low, the fuse is still OK.
The Multimeter is to be set at 20k
Start by setting your multimeter to the 20k setting, preparing it to measure up to 20,000 ohms. This adjustment is crucial for accurately gauging the electrical resistance and ensuring the integrity of the fuse.
Connect the Test Plugs
Verify the ohm measuring probes are plugged in.
Verify the Verification Tools
To conduct a test, just press the stubs of the testing leads together. The resistance should be very low, or the multimeter should read zero. The multimeter should display 1 when the tips are separated, indicating 100% resistance.
Locate an Area Free of Metal
Ideally, you should choose a surface that is not made of metal so that you do not get a distorted reading.
Taking Out the Fuse
The multimeter might cause an electrical overload, therefore it’s important to take the precaution of removing the vehicle’s fuse first.
Examine the Fuse
Using your eyes, make sure the wire within the fuse is in good shape. A blown fuse signified by a broken wire will need to be replaced. Listed below is an illustration showing a functional fuse on the left and a blown fuse on the right.
Using the Test Leads, Check the Fuse
Connect a probe to either end of the fuse and check it out. Near zero on the multimeter is ideal. If the number 1 appears, it means the fuse has reached its maximum resistance and has to be replaced. Fuses are either serviceable or disposable unless the vehicle is older than 30 years.
Our aim with this guide on digital multimeter fuse testing is to empower you with the knowledge to navigate electrical systems more proficiently, enhancing your troubleshooting skills.
Conclusion
A multimeter is often used to measure voltage and resistance, but can also be used to check the status of a battery or determine if a fuse has blown. In school, you may be asked to use your multimeter for a wide range of testing and diagnostic purposes as an aspiring electrician or engineer. If the fuse is open, the ohms will be quite high, but if they are low, the fuse has blown. To test the resistance, you’ll need a multimeter with resistance reading capabilities. The multimeter might cause an electrical overload, so it’s important to take the precaution of removing the vehicle’s fuse first.
Fuses are either serviceable or disposable unless the vehicle is older than 30 years. If the number 1 appears, it means the fuse has reached its maximum resistance and needs to be replaced.
Content Summary:
- While still in school, you may be asked to use your multimeter for a wide range of testing and diagnostic purposes as an aspiring electrician or engineer.
- Although a multimeter is often used to measure voltage and resistance, it may also be used to test the status of a battery or determine if a fuse has blown.
- And the latter is what we’ll be looking at today: how to use a multimeter to check a fuse.
- Fuse testing is a basic, quick, and easy process.
- The first step is to measure its resistance, which indicates how well material conducts electricity and how well it dampens voltage fluctuations.
- Fuses are passive components used in circuits where voltage spikes are possible.
- This means that an electrician has to be familiar with checking and changing fuses.
- A blown fuse is something that has happened to almost everyone at some point, and most of us have replaced it.
- However, not all fuses are inexpensive, and if you don’t have a spare on hand, you’ll need to make a trip to the hardware store or auto parts shop.
- Since we work as an electrician, we have had to test countless fuses over the years to determine whether or not they were indeed blown before replacing them.
- Before going out of your way to buy and install a new fuse, you should check to determine if the one in question has actually blown.
- Fuse testing is simple, just requires a few pennies worth of equipment, and may save you time and money.
- Electrical overloads can be prevented by utilizing fuses, which consist of a short length of wire housed in a particular enclosure that is designed to melt in two.
- We only need to check to see if that cable has completely severed.
- While the wire may be visible via a tiny window in some fuses, the view is typically poor, the wire is typically rather little, and mistakes are possible.
- A quick 30-second check will reveal the truth without room for error.
- If the circuit is subjected to more current than it can safely manage, the fuse will blow.
- A blown fuse indicates an electrical short between two wires or between the power line and the ground (car body).
- If the wiper or blower motor is stuck and turned on, for instance, it will require more power from the outlet and may blow the fuse.
- If a winding within the motor is shorted, the same thing might happen.
- We identified many widespread issues that lead to fuse blowing: When a metal object (such as a penny) falls into it or when a faulty accessory is connected to the front auxiliary power socket, these are the most prevalent causes of a malfunction (cigarette lighter socket).
- When the trunk lid or liftgate is opened, the wire harness bends, causes a short circuit, and blows the fuse for the brake lights or taillights.
- It is also possible to blow a fuse by using the incorrect bulb in the car’s headlights or taillights.
- Trailer wiring that has been chafed or scraped causes an electrical short.
- The fuse in the car’s electrical system was blown because a wire harness in the engine compartment had worn through.
- When the insulating on the main wiring harness breaks, it can cause a short causing the fuse to blow, an issue that is frequent in some older Mercedes-Benz vehicles.
- Like the continuity tester, a multimeter has two leads.
- A multimeter, on the other hand, can measure current, voltage, and resistance across a wide range of values.
- Multimeters come in a wide variety of forms, including those that are auto-ranging (no need to select a range) and those that use a needle or digital display to display the reading.
- The initial step in using any multimeter is to switch the setting to resistance ().
- If there are many ranges to pick from, go with the lower one (K on the dial represents thousand, so 2K equals 2000).
- Put one probe on a continuity tester and touch it to each fuse contact.
- If the meter reads 1 ohm or less, the fuse is fine; if it reads infinite, the fuse has blown.
- Wiggle the sensors on the fuses contact, clean them, and try again if you get an intermediate reading of several ohms.
- Determine the ohms with a multimeter.
- To test the resistance, you’ll need a multimeter with resistance reading capabilities.
- Verify the ohm measuring probes are plugged in.
- To conduct a test, just press the stubs of the testing leads together.
- The resistance should be very low, or the multimeter should read zero.
- The multimeter should display 1 when the tips are separated, indicating 100% resistance.
- Ideally, you should choose a surface that is not made of metal so that you do not get a distorted reading.
- The multimeter might cause an electrical overload, therefore it’s important to take the precaution of removing the vehicle’s fuse first.
- Using your eyes, make sure the wire within the fuse is in good shape.
- A blown fuse signified by a broken wire will need to be replaced.
- Listed below is an illustration showing a functional fuse on the left and a blown fuse on the right.
- Check the Fuse Connect a probe to either end of the fuse and check it out.
- Near zero on the multimeter is ideal.
- If the number 1 appears, it means the fuse has reached its maximum resistance and has to be replaced.
- Fuses are either serviceable or disposable unless the vehicle is older than 30 years.
- We trust that this little instruction on digital multimeter fuse testing will help you better understand electrical systems.
