How to Use a Multimeter to Troubleshoot Electronics Projects

Welcome to our latest tutorial that promises to be a valuable resource for all DIY enthusiasts, hobbyists, and budding electricians alike. Today, we’re diving into the fascinating world of electronics troubleshooting with a very handy and versatile tool: the multimeter. This all-in-one gadget is an essential addition to your toolkit whether you’re debugging your latest Arduino project, repairing a motorized prop, or simply curious about the invisible electrons flowing in your circuits. Don’t let its complex look intimidate you! By the end of this guide, you’ll learn how to wield the multimeter with confidence to troubleshoot and bring your electronics projects to life. So, sit back, grab your multimeter, and let’s turn those mysterious circuit problems into mere minor hitches on the journey to your next great invention.

In This Multimeter Tutorial:

What is a Multimeter?

A multimeter, also known as a volt-ohm meter, is a handheld device that combines several electronic measurement functions in one unit. A typical multimeter can measure voltage, current, and resistance.

An example of a multimeter that can measture voltage, current, resistance, check continuity and more!

This is my multimeter and I’ve had it for over a decade. At the time I paid around $20 for it and it’s paid for itself several times over not just with electronics projects but in troubleshooting household and car issues as well. Your typical digital multimeters all have the same core features but the center dial can look different from model to model. The economy models have a center dial with more settings because you have to set the range you want to measure within. The more expensive multimeters have more features, the main one being auto-ranging. The dials on an auto-ranging multimeter are more simple because it automatically detects what range you’re measuring.

If you work mostly with DC circuits, an economy multimeter like mine will take you a long way but I don’t recommend them for AC circuit work. If you intend to use your multimeter primarily for household electrical work, then I recommend getting one that’s more robust.

Here are the key functions nearly all multimeters have:

  • Voltage Measurement: A multimeter can measure both alternating current (AC) and direct current (DC) voltages. This is important when testing for the presence of voltage or confirming the correct output from a power supply, for instance.
  • Current Measurement: Multimeters can measure both AC and DC currents. This function is often used when diagnosing circuits to determine whether the necessary amount of current is flowing.
  • Resistance Measurement: Multimeters are used to measure the resistance of a component or a section of a circuit, helping to identify if a resistor or other component is functioning correctly.
  • Continuity Testing: This function is used to check if there is a continuous path for electricity to flow between two points. This is especially useful when checking for broken wires or connections.
  • Capacitance and Frequency Measurements: Some advanced multimeters can measure capacitance (the ability of a component to store an electric charge) and frequency (how often a periodic event occurs in a given time).
  • Temperature Measurement: Some multimeters also include a temperature sensor.

Multimeters come in two types: analog and digital. Analog multimeters use a needle and scale to display measurements, while digital multimeters (DMMs) display measurements numerically on an LCD screen. Digital multimeters are more common and tend to be more accurate than their analog counterparts.

Parts of a Multimeter

Getting familiar with the different parts of a multimeter is an essential first step in leveraging this versatile tool for electronics troubleshooting and learning. A multimeter, whether digital or analog, consists of several key components, each playing a critical role in the tool’s operation. From the central selection knob and display screen, to the probe ports and the test probes themselves, each part has a specific function that enables the multimeter to measure various electrical properties accurately and effectively. In this section, we’ll dive deeper into the individual parts of a multimeter, ensuring you have a thorough understanding of their functions, which will enhance your ability to use this tool efficiently and safely in your projects.

A typical multimeter, particularly a digital one, consists of several parts:


This is where the measurements read by the multimeter are shown. On a digital multimeter, this is typically a liquid crystal display (LCD). The display will show the measurement in the appropriate units (volts, ohms, amps, etc.)

Selection Knob

The selection knob (or dial) allows you to select the function and the range of the measurement. This includes options for measuring voltage (V), resistance (Ω), and current (A), as well as whether the measurement is for direct current (DC) or alternating current (AC).

The different sections labeled on a multimeter dial for measuring voltage, current and resistance in both AC and DC.

I’ve labeled the sections we’re going to be working with in this multimeter tutorial but you can see that even my economy multimeter has more functionality like reading capacitance, frequency, and temperature. It can also test transistors and capacitors.

My multimeter is not auto-ranging so within each section you’ll see some values that increment from low to high. Whatever value you select within a section, the multimeter will read up to that value but it won’t detect anything past it. If you don’t know what value you expect out of your circuit, start with the highest one and work your way down.

Ports (or Terminals)

These are where you plug in the test leads. The typical ports are COM (common terminal, usually connected to ground or zero potential), VΩmA (used for voltage, resistance, and low current measurements), and 10A or 20A (used for high current measurements).

My multimeter has a separate port (white) for measuring low current up to 200mA which is sufficient for most microcontroller projects. If you’re using the low current port and your measurement exceeds it’s limit, you’ll blow the fuse on the multimeter. My 200mA MAX port is also labeled FUSED so I know that if I go past that when using this port, I’ll blow the fuse. Some mutlimeters max out at 10A. Mine can go up to 20A (yellow port) but you’ll notice it’s labeled UNFUSED so I definitely don’t want to exceed this both for my own safety and not wanting to damage my multimeter. If you’re unsure of what your current reading is going to be (but know it won’t exceed the max), plug the red probe into the 10A/20A port first and work down from there.

The ports on a multimeter including COM, Volts/Ohm/Hz, 200mA fused and 20A max unfused.

I’ve blown the fuse on this very multimeter a few times and it’s still kicking. Luckily it was never by much so I didn’t cause any permanent damage. I’ll show you how to change the fuse later on in this tutorial in case it happens to you. It’s all part of the learning process.

Test Leads

These are two wires that are used to connect the multimeter to the device or circuit being tested. One lead is typically red (positive) and the other black (negative). Each lead has a metal probe at one end (for contacting the device under test) and a connector, called a banana jack, at the other (for plugging into the multimeter).

Test leads for a multimeter that has probes on one end for taking measurements and banana jacks on the other for plugging into multimeter ports.

I recommend getting banana-to-alligator clip leads to free up your hands. In addition, regular alligator clips come in handy to act as an extension cord for when you can’t get your test probes to reach the part of the circuit you want to measure.


Besides the main selection knob, some digital multimeters have buttons to choose additional functions or settings. This might include a button to hold the current reading on the display, to switch between automatic and manual range selection, to test diodes, or to measure capacitance or frequency.

The buttons on a digital multimeter including power and hold.

My multimeter just has a red power ON/OFF button and a HOLD button. When taking a reading, as soon as you remove the probes from the component or circuit, the reading will immediately disappear from the screen. The HOLD button will lock that reading on the screen so you can remove your leads and not lose the reading. This is useful for when you need to write your readings down.

Battery & Fuse Compartment

Most multimeters are battery-operated, so they will have a compartment for the battery. This is usually at the back of the multimeter. My multimeter is powered by a 9V battery and I have to take the protective case off first in order to access the battery compartment.

The battery and fuse compartment located in the back of the multimeter.

Inside the multimeter, there are usually one or two fuses designed to protect from overload on the current ranges. I have one 200mA / 250V fuse located right next to the battery. You can buy replacement multimeter fuses online. Just make sure to match the ratings.

Remember that different models of multimeters may have more or fewer features and therefore yours may have more or fewer parts than mine.

Measure Voltage with a Multimeter

Measuring voltage with a multimeter is a helpful skill in a wide range of electronics projects. For instance, when building a new circuit, you might need to verify that the voltage supply is within the expected range for your components to function correctly. If you’re troubleshooting a malfunctioning device, measuring voltage can help determine if a power supply is delivering the correct voltage, if a battery is charged, or if a component is receiving the voltage it needs to operate. In addition, voltage measurements can assist in diagnosing issues like unwanted voltage drops across connections or components, which might suggest a problem like a loose connection or a failing component. In all of these scenarios, knowing how to use a multimeter to measure voltage is an essential skill for the electronics enthusiast.

Remember, safety first. Don’t attempt to measure voltage if it exceeds your multimeter’s input limits. For circuits over 30V, there’s a risk of shock so take precautions like wearing protective equipment and take your time as you work through the troubleshooting steps.

Example 1: How to Test a Battery

As much as I try to keep my used batteries separate from the new ones, they always find a way to intermingle. For any battery-powered circuit, the first thing I do is test my battery juice. That way you can rule out a faulty power supply from the start.

Testing a battery with a multimeter is a relatively simple process. Here’s how to measure a AA battery with a multimeter:

How to measure a AA battery with a multimeter including dial setting, ports to use and test lead positions.

  1. Identify the Correct Section: First, find the section of the multimeter dial you’ll be working with. In our case, we’ll be measuring in the DC volts section. This is usually indicated by a ‘V’ next to a symbol that looks like a straight line over three dashed lines.
  2. Choose the Range: If your multimeter isn’t auto-ranging, select the appropriate range for the voltage you expect to measure. A fresh AA battery, for example, should have a voltage of about 1.5V, so set the dial to 2V. This tells the multimeter to measure voltage up to 2 volts.
  3. Prepare the Test Leads: Plug the black test lead into the COM port on the multimeter and the red test lead into the VΩmA port. In my case, the port is labeled V/Ω/Hz.
  4. Test the Battery: Turn on the multimeter and touch the metal tip of the black probe to the negative terminal (-) of the battery and the red probe to the positive terminal (+).
  5. Read the Voltage: The multimeter will display the voltage of the battery. For a new, fully charged AA battery, you would expect a reading of around 1.5V. If the battery is partially or fully discharged, the reading will be lower. My reading is 1.488V and you’ll notice some slight corrosion on it from improper storage so I’m just shy of 1.5V.

If you’re testing a rechargeable battery, keep in mind that the voltage can vary depending on the specific type of battery. For instance, a fully charged NiMH AA rechargeable battery will typically read a bit lower than 1.5V, while a Li-ion rechargeable battery might read higher.

What happens if I switch the red and black probes?

Nothing bad will happen. The reading on the multimeter will be the same magnitude for the voltage reading but with a reversed polarity. The red probe of a multimeter is typically connected to the point in a circuit that is at a higher potential, while the black probe is connected to the lower potential or ground. If you reverse these connections, the multimeter will indicate that the voltage is negative. This is because the multimeter sees the voltage at the black lead as being higher than the red lead, which is the reverse of the normal setup. So, if you were expecting a reading of +5 volts and instead get -5 volts, it simply means the probes are reversed. The actual voltage magnitude remains the same, it’s just the indicator of polarity that changes.

An example of a multimeter showing a negative reading when measuring voltage of a battery because the red and black probes are switched.

Here’s what it looks like when I take the same reading from the battery except that I’ve switched the red and black probes. The magnitude (value) is the same but the polarity is reversed (negative sign).

Measure the Voltage of a 9V Battery with a Multimeter

Quiz time! Let’s see if you can measure the voltage of a 9V battery with your multimeter. As the name implies, we’d expect to get around 9V for a good battery. Go!

Trying to test the voltage of a battery with a multimeter but forgetting to set the proper range will give you an error.

I got 1 volt? Geez, this battery is deader than dead. Maybe it’s all that corrosion on it. Or… can you spot my mistake? Look closely at the dial.

In my haste to beat you guys, I forgot to set the dial properly. Right now, I can only read up to 2 volts and that’s why I’m getting the “1” error. The error will look like this on most multimeters but yours can look a little different.

The next higher option is 20, which would let the multimeter read up to 20 volts. Let’s try that!

A multimeter testing the voltage of a 9V battery.

That’s better …well almost. This battery has a voltage of 7.45 which is nearing the end of its usable life.

Example 2: How to Measure Voltage in a Circuit

While testing batteries is a vital part of building electronics projects, let’s move on to a real world example. In this case, I have a circuit with an LED, current-limiting resistor and 3V battery power supply. For some reason, the LED barely lights up at all. Something isn’t right with this circuit – let’s investigate!

A simple LED circuit to troubleshoot with a multimeter.

In order to measure voltage within a circuit, it has to be powered on. Most of your circuits will have more than one component so we want to try and isolate where the problem is. Let’s start by measuring the voltage across the entire circuit.

A multimeter measuring the voltage in an LED circuit.
A close up of how the multimeter probes should be positioned to measure voltage in a circuit.

  1. Select the DC Voltage Range – Since we have a 3V power supply I know I have to set my dial to 20V because the 2V setting is too low.
  2. Place the Leads – Take your red probe and touch it to where the voltage is coming into the circuit. This would be the first leg of the resistor getting power from the battery. Next, touch the black probe to where the voltage is leaving of the circuit. This is the cathode or negative leg of the LED. Measuring from where the voltage is going in to the resistor and then where ground is on the LED, we should see the full voltage of the circuit, which we expect to be around 3V.
  3. Read the Voltage – Look at the multimeter display to see the voltage reading. My reading is 3.19 volts so we are giving the circuit enough voltage to light up the LED which has a typical forward voltage of 2.0 volts.

Next, let’s see how much voltage the LED is using. This is known as the voltage drop across the LED. Place one probe on each leg of the LED. It doesn’t matter which probe. You’ll still get the same reading, only negative if the probes are switched.

A multimeter measuring the voltage drop across an LED.
Place the multimeter probes, one on each leg of the LED, to measure voltage drop.

If the red LED needs about 2 volts to operate, then 1.6 volts is too low. No wonder it’s not turning on. Taking a closer look at the circuit, it looks like I’m using a 100K resistor which is way too much for this circuit. You can use Ohm’s Law to calculate the exact resistor value you need in a circuit but for LEDs anything from 330 – 1K Ohms will do depending on the power supply voltage.

Here’s the circuit again, with a 330 Ohm resistor instead:

A multimeter measuring the voltage drop across an LED showing the placement of the probes - one on each leg of the LED.

I got a reading of 1.88 volts which is close the 2 volts which is required by the LED to function. The LED could glow a little brighter if we used an even lower value resistor like 50 Ohms but for demonstration purposes the 330 is fine.

Remember, when measuring voltage, the multimeter is connected in parallel (across) with the part of the circuit you’re testing. It’s different from measuring current, where the multimeter has to be part of the circuit (connected in series). I’ll show you how to do that next.

Measure Current with a Multimeter

Understanding how to measure current with a multimeter is just as important as measuring voltage for your electronics projects for troubleshooting components and entire circuits, analyzing performance, and ensuring safety. With troubleshooting, it helps identify components that draw too much or too little current, leading to potential failures or inefficiencies. By monitoring the current flow through various parts of a circuit, it provides insights into the performance of your design and aids in optimizing power consumption. Moreover, it plays a vital role in safety, as excessive current can cause overheating or damage to components, and even pose a risk of fire. Hence, measuring current is fundamental to the successful and safe implementation and operation of electronics projects.

Example: How to Measure Current in a LED Circuit

Measuring current using a multimeter involves a slightly different approach compared to measuring voltage or resistance, as the multimeter needs to be connected in series with the load (part of the circuit where current is to be measured). This means the circuit path must be broken to place the multimeter in line with the circuit.

It’s very important to note that the circuit must be powered off when you’re connecting or disconnecting the multimeter for current measurements, otherwise, you risk a short circuit or damaging the multimeter. Also, make sure not to exceed the maximum current rating of the multimeter to avoid damaging it or causing a safety issue. If you’re not sure what current value to expect then plug your red probe into the 10A or 20A port and check the value. If it’s under what’s listed on the lower range port then you can jump over there for a more accurate reading. If you exceed the current limit for the low range port then you’ll blow the fuse on your multimeter or even damage it.

Let’s measure the current in the LED circuit from the previous example. Here are the steps:

A multimeter connected in series reading the current in an LED circuit.

  1. Prepare the Multimeter: First, turn the selection knob on the multimeter to the current setting, usually represented by A (for amps). Select DC for direct current or AC for alternating current as needed. Since our circuit is powered by a battery, we’re going to be working in the DC current section which is denoted by an “A” with a straight line on top and three dashed lines on the bottom.
  2. Select Range: If your multimeter is not auto-ranging, select the appropriate range for the current you expect to measure. If you’re not sure what reading to expect for your circuit, start with the highest range, 10A or 20A (depending on your multimeter) to get a ballpark reading and fine-tune down from there. Don’t forget to move your red probe to the 10A/20A jack if you do this! For my circuit, I don’t expect get over 200mA so I’m starting at that setting on the dial.
  3. Configure Test Leads: Plug the black test lead into the COM port on the multimeter. The red lead goes into the port labeled for current measurement. Sometimes this is a separate port or it could be the same port used for voltage and resistance measurements. My multimeter has a separate white port for taking low range current readings up to 200mA. Since I don’t expect to go over that, it’s safe to start with this port. Otherwise, I start with the red probe in the 20A port to get a ballpark reading. Remember to move your red probe into the low current port when switching from the 20A/10A setting to the lower current ranges on the dial.
  4. Turn Off Power: Power off the circuit and disconnect it where you want to measure the current.
  5. Connect Multimeter in Series: Connect the multimeter in series with the circuit. This means one probe should be connected to the side of the break leading towards the power source and the other probe to the side leading towards the load (the part of the circuit you’re interested in). This is where having alligator clips comes in handy! Be sure none of the probes or metal portions of the alligator clips touch each other.
  6. Turn On Power: Power the circuit back on.
  7. Read Current: The current value will be displayed on the multimeter’s screen. With the 330 Ohm resistor in place, I get a current of 3.83 mA. You can see that I dialed down from 200mA to 20mA to get a more accurate reading.
  8. Safety: After you finish your measurement, first remove the red probe (or red alligator clip) and then the black one, then power off the circuit.

Here the same circuit but I swapped in the 100K Ohm resistor instead:

A multimeter connected in series reading the current in an LED circuit.

The current reading is .015 mA! No wonder the LED was barely lighting up at all! The 100K Ohm resistor is too high a value for this circuit.

Didn’t blow a fuse? Awesome! Let’s move on to reading resistance.

Oh but wait! After you’re done measuring current ALWAYS reset your multimeter back into voltage reading mode AND place the red probe back into the voltage port. It’s a common scenario to quickly pick up a meter to measure the voltage across two pins. If your meter is left in current mode, the display won’t show the voltage and will instead read 0.00, indicating there’s no current flowing between VCC and GND. However, in that moment, you’ll have unintentionally created a direct connection between VCC and GND through your meter, which will blow the 200mA fuse – oops! This is easy to do, especially when you’re in the throes of troubleshooting. So always make sure that your meter is set to a safe mode, typically the voltage reading mode, before storing it away.

Measure Resistance with a Multimeter

Resistance, which quantifies how much a component or circuit impedes the flow of electricity, impacts virtually every aspect of an electronic device’s behavior. Measuring resistance with a multimeter is useful when you need to confirm the value of a resistor, especially when the color bands are hard to read or non-existent. It’s also crucial when troubleshooting a circuit, where you might need to identify a broken connection (indicated by an infinite resistance) or a short circuit (indicated by a very low or zero resistance). Also, if you’re designing a circuit and need to ensure that components are paired appropriately based on their resistance values, a multimeter is your indispensable tool. For instance, confirming the correct value of a resistor before it’s used to limit current to an LED can prevent the LED from burning out. In all these scenarios, the ability to measure resistance with a multimeter is a key skill in the electronics hobbyist’s toolkit.

Example: How to Check the Value of a Resistor

Resistors have color bands to indicate their values. There are calculators online that can tell you the resistance value based on the resistor’s color bands. I find it much faster to use my multimeter when I find myself in a situation where I’m working with components that need different values and they got mixed up in a pile on the workbench. Depending on the manufacturer, the colors of the bands may look a little off. For instance, red and brown can look similar and orange can look like red because of the printing process. So rather than squinting my eyes, I take a quick measurement.

Let’s measure the resistance of this “mystery” resistor:

Measuring the resistance value of a resistor with a multimeter.

  1. Turn Off Power: Power must be removed from the circuit when you’re measuring resistance. This means disconnecting the power source or removing the component from the circuit to measure it.
  2. Select Resistance on the Multimeter: Turn the selection knob on the multimeter to the resistance setting, usually indicated by the Greek letter Omega (Ω).
  3. Select the Range: If your multimeter is not auto-ranging, you need to select a suitable range for the resistance you expect to measure. If you’re unsure, start with a higher range and work your way down. I know the highest value resistor I have on the workbench is 100K so I set my dial to 200K. This will allow my multimeter to read up to 200K Ohms.
  4. Connect Test Leads: Plug the black test lead into the COM port on the multimeter, and the red test lead into the port labeled VΩmA (for voltage, resistance, and milliampere measurements).
  5. Measure Resistance: Touch the metal tips of the probes to the two ends of the component or section of the circuit where you wish to measure resistance. The probe orientation doesn’t matter when measuring resistance – you’ll get the same reading whether you connect the red probe to one end and the black probe to the other, or vice versa.
  6. Read the Resistance: The resistance will be displayed on the multimeter’s screen. If you see a ‘1’ or ‘OL’ (overload) displayed, this means the resistance is too high for the selected range. In this case, select a higher range.

I get a reading of 98.9K Ohms so I know this is a 100K resistor. Why the discrepancy? Many resistors have a 5% tolerance. This means that the color codes may indicate 100K Ohms, but because of differences in the manufacturing process a 100K resistor could be as low as 95K or as high as 105K.

Measure Continuity with a Multimeter

Continuity testing is essentially a simple yes/no test to see if an electrical path exists between two points. This is indispensable in troubleshooting and diagnostics, as it allows you to quickly and accurately identify breaks in circuits, verify solder joint connections, or check if switches, fuses, and wires are functioning properly. It’s an easy way to ensure that connections that should be present are there and that those which shouldn’t be, aren’t. In effect, checking for continuity is akin to making sure all the roads on a map are correctly connected, providing a smooth flow of current for your electronics projects. This makes it an essential skill for maintaining the health and functionality of any electronic device or project.

Example: How to Test Continuity for Wires & Components

I usually buy electronics components in packs because it’s far more economical than buying one at a time. For mass-produced components, it’s not uncommon for there to be a dud in the pack so it’s good to get in the habit of testing your components before you even incorporate them in your circuits. Luckily. testing for continuity with a multimeter involves only one setting and the procedure is the same for just about any component.

To measure continuity with a multimeter, follow these steps:

A multimeter testing the continuity of a wire.
A multimeter testing the continuity of a switch.
A multimeter testing the continuity of an LED.

  1. Turn Off Power: Always make sure the circuit is not powered before you start the continuity test. Doing a continuity test on a live circuit could damage the multimeter or the circuit.
  2. Select Continuity on the Multimeter: Turn the selection knob on the multimeter to the continuity setting. This is usually near the resistance section represented by a symbol that looks like audio waves. Sometimes there’s even a diode symbol next to the audio waves.
  3. Connect Test Leads: Plug the black test lead into the COM port on the multimeter, and the red test lead into the port labeled VΩmA (for voltage, resistance, and milliampere measurements).
  4. Test for Continuity: Touch the metal tips of the probes to the two points in the circuit that you want to test for continuity. It doesn’t matter which color probe goes to which point, as continuity is non-directional. Above you can see some examples of how to test for continuity including wires, switches and LEDs. The only time when probe orientation is important is for testing LEDs or diodes. With this components place the red probe on the positive side and black probe on the negative side. You’ll notice that LEDs light up dimly and that’s how you know they’re working.
  5. Listen for a Tone: If there is a complete path (continuity) through the circuit, many multimeters will emit a beep or continuous tone. This is very useful for rapid testing of many connections in a short period of time. LEDs typically don’t give off a tone but you’ll see them light up dimly if they’re good.
  6. Read the Display: Some multimeters also show a value on the display. If the resistance is very low (a few ohms or less), then the circuit has good continuity. If the display shows “OL” (overload), then there is no continuity i.e., the resistance is too high or infinite. My multimeter shows a 1 when using the continuity feature.

Remember, continuity is a simple check to see if a circuit is complete by verifying that current can flow through it unimpeded. It does not verify the correctness of a circuit’s functionality, that requires a more detailed analysis, like checking voltage, current, and resistance as needed.

How to Change a Multimeter Fuse

Changing the fuse on a multimeter might become necessary when the fuse has blown, which is a safety feature designed to protect both the multimeter and yourself. A fuse may blow when the current flowing through it exceeds its rated capacity. This can happen if you try to measure current incorrectly, such as trying to measure current on a high-energy circuit that exceeds the fuse’s rating or forgetting to move your probe to the higher 10A/20A port before taking a measurement that exceeds that of the 200mA port. I’ve definitely been guilty of the latter when going from troubleshooting lower current electronics projects to higher powered circuits like motors, automotive or household without taking my time to double check my settings and probe positions. As soon as my probes touched the circuit I only got a reading of 0.00. Sure enough when I looked down at my multimeter I realize that I forgot to move my red probe to my 20A port!

Another common mistake that I’ve also made is measure current on a bread board by accidentally touching VCC to GND – oops. This will immediately short power to ground through the multimeter causing the bread board power supply to brown out. As the current rushes through the multimeter, the internal fuse will heat up and then burn out. When troubleshooting a circuit, you’ll often jump back and forth from measuring voltage (in parallel) to measuring current (in series). At times when I’ve rushed things, I forget to reset the dial and try to measure current with my probes in the parallel position.

Changing the fuse on a multimeter by prying the blown one out and replacing it with a new fuse.

Changing the fuse is a really easy process. It’s typically located in a compartment in the back. You may have one or two fuses depending on your multimeter. I only have one – for the 200mA port. They are typically held in place with metal clips. Just pry out the blown fuse and replace it with a new one of the same rating. I recommend you buy a pack of fuses so you’re always covered. It’s even more frustrating when you’re closing in on the problem, blow a fuse, and have to wait for replacements. By then I forget where I am and need to start over.

Troubleshooting electrical gremlins can be a frustrating process and this has caused me to try and get through it quickly. Take your time between measurements to check your dial and port settings!

How do I know I’ve blown a fuse in my multimeter?

When a fuse blows, it usually won’t make any noise so you may not realize it right away. The main sign that your multimeter’s fuse has blown is that it will no longer provide accurate readings for current, and in some models, it may affect other measurement functions as well. In my case, my multimeter will work fine in all settings except current. I’ll always get a 0.00 reading and that’s how I know I probably blew the fuse. A blown fuse should be replaced with a new one of the same rating as specified by the multimeter’s manufacturer. It’s important to remember that the fuse is there for safety, and ensuring it’s functioning correctly is crucial for safe operation of the multimeter.

Practice Troubleshooting with a Multimeter Often

Mastering the use of a multimeter is a pivotal step in your journey towards becoming proficient in troubleshooting electronics projects. The more you practice using it with your circuits – even the ones that work the very first time – the faster you’ll be able to identify problems with the circuits that don’t. This versatile tool, with its capacity to measure voltage, current, resistance, and check continuity, provides invaluable insights into the workings of your circuits, helping to identify faults, verify component functionality, and ensure safe operations. By understanding how to correctly and safely use a multimeter, you’ll equip yourself with a critical skillset that forms the backbone of successful electronics troubleshooting.

Some links in this post are to affiliate sites. If you purchase something through them, I may earn a small commission — which costs you nothing! I am very grateful for your support when you use my links to make a purchase.

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