Introduction

Every fixer should know their way around a multimeter, which has just north of a zillion uses for testing electronic components and circuits. Follow along to master the three most basic functions of a multimeter.

Part 1: Testing Continuity

Part 2: Testing Voltage

Part 3: Testing Resistance

Parts

No parts required.

A continuity test tells us whether two things are electrically connected: if something is continuous, an electric current can flow freely from one end to the other.
  • A continuity test tells us whether two things are electrically connected: if something is continuous, an electric current can flow freely from one end to the other.

  • If there's no continuity, it means there is a break somewhere in the circuit. This could indicate anything from a blown fuse or bad solder joint to an incorrectly wired circuit.

  • Continuity is one of the most useful tests for electronics repair.

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To begin, make sure no current is running through the circuit or component you want to test. Switch it off, unplug it from the wall, and remove any batteries. Plug the black probe into the COM port on your multimeter.
  • To begin, make sure no current is running through the circuit or component you want to test. Switch it off, unplug it from the wall, and remove any batteries.

  • Plug the black probe into the COM port on your multimeter.

  • Plug the red probe into the VΩmA port.

Why only in VΩmA not in 10A

Geetha - Reply

Great question! The VΩmA port is rated up to 200 milliamps (mA), which is the correct range for this demonstration. If you're not sure how much current you're dealing with, go ahead and start with the red probe in the 10 A port instead—it's less sensitive, but can take up to 10 A without blowing a fuse.

Jeff Suovanen -

Why do we need to make sure that no current is running through the circuit?

When there is another parallel branch with 24VDC power and 4-20mA output, the value of the resistance measured comes as zero. Whats the reason?

Fraz - Reply

Switch on your multimeter, and set the dial to continuity mode (indicated by an icon that looks like a sound wave). Not all multimeters have a dedicated continuity mode. If yours doesn’t, that’s okay! Skip to Step 6 for an alternate way to perform a continuity test.
  • Switch on your multimeter, and set the dial to continuity mode (indicated by an icon that looks like a sound wave).

    • Not all multimeters have a dedicated continuity mode. If yours doesn’t, that’s okay! Skip to Step 6 for an alternate way to perform a continuity test.

I want to search the resistance of gold and see if I have some

Joel Stegner - Reply

The multimeter tests continuity by sending a little current through one probe, and checking whether the other probe receives it. If the probes are connected—either by a continuous circuit, or by touching each other directly—the test current flows through. The screen displays a value of zero (or near zero), and the multimeter beeps. Continuity!
  • The multimeter tests continuity by sending a little current through one probe, and checking whether the other probe receives it.

    • If the probes are connected—either by a continuous circuit, or by touching each other directly—the test current flows through. The screen displays a value of zero (or near zero), and the multimeter beeps. Continuity!

    • If the test current isn't detected, it means there's no continuity. The screen will display 1 or OL (open loop).

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To complete your continuity test, place one probe at each end of the circuit or component you want to test. As before, if your circuit is continuous, the screen displays a value of zero (or near zero), and the multimeter beeps.
  • To complete your continuity test, place one probe at each end of the circuit or component you want to test.

  • As before, if your circuit is continuous, the screen displays a value of zero (or near zero), and the multimeter beeps.

  • If the screen displays 1 or OL (open loop), there's no continuity—that is, there's no path for electric current to flow from one probe to the other.

  • Continuity is non-directional, meaning it doesn't matter which probe goes where. But there are exceptions—for instance, if there's a diode in your circuit. A diode is like a one-way valve for electricity, meaning it will show continuity in one direction, but not in the other.

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If your multimeter doesn't have a dedicated continuity test mode, you can still perform a continuity test. Turn the dial to the lowest setting in the resistance mode.
  • If your multimeter doesn't have a dedicated continuity test mode, you can still perform a continuity test.

  • Turn the dial to the lowest setting in the resistance mode.

    • Resistance is measured in ohms, indicated by the symbol Ω.

How do I test Amps ( ouput from a battery charger)

jpretorius10 - Reply

Thank u so much

Kademe Eric - Reply

In this mode, the multimeter sends a little current through one probe, and measures what (if anything) is received by the other probe. If the probes are connected—either by a continuous circuit, or by touching each other directly—the test current flows through. The screen displays a value of zero (or near zero—in this case, 0.8). Very low resistance is another way of saying that we have continuity.
  • In this mode, the multimeter sends a little current through one probe, and measures what (if anything) is received by the other probe.

    • If the probes are connected—either by a continuous circuit, or by touching each other directly—the test current flows through. The screen displays a value of zero (or near zero—in this case, 0.8). Very low resistance is another way of saying that we have continuity.

    • If no current is detected, it means there's no continuity. The screen will display 1 or OL (open loop).

Add Comment

To complete your continuity test, place one probe at each end of the circuit or component you want to test. It doesn't matter which probe goes where; continuity is non-directional.
  • To complete your continuity test, place one probe at each end of the circuit or component you want to test.

    • It doesn't matter which probe goes where; continuity is non-directional.

  • As before, if your circuit is continuous, the screen displays a value of zero (or near zero).

  • If the screen displays 1 or OL (open loop), there's no continuity—that is, there's no path for electric current to flow from one probe to the other.

Add Comment

Plug the black probe into the COM port on your multimeter. Plug the red probe into the VΩmA port.
  • Plug the black probe into the COM port on your multimeter.

  • Plug the red probe into the VΩmA port.

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Switch on your multimeter, and set the dial to DC voltage mode (indicated by a V with a straight line, or the symbol ⎓). Virtually all consumer electronic devices run on DC voltage. AC voltage—the kind that runs through the lines to your house—is considerably more dangerous, and beyond the scope of this guide.
  • Switch on your multimeter, and set the dial to DC voltage mode (indicated by a V with a straight line, or the symbol ⎓).

    • Virtually all consumer electronic devices run on DC voltage. AC voltage—the kind that runs through the lines to your house—is considerably more dangerous, and beyond the scope of this guide.

  • Most multimeters are not autoranging, meaning you will need to set the correct range for the voltage you expect to measure.

    • Each setting on the dial lists the maximum voltage it can measure. So for example, if you expect to measure more than 2 volts but less than 20, use the 20 volt setting.

    • If you're not sure, start with the highest setting.

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Place the red probe on the positive terminal, and the black probe on the negative terminal. If your range was set too high, you may not get a very accurate reading. Here the multimeter reads 9 volts. That's fine, but we can turn the dial to a lower range to get a better reading.
  • Place the red probe on the positive terminal, and the black probe on the negative terminal.

    • If your range was set too high, you may not get a very accurate reading. Here the multimeter reads 9 volts. That's fine, but we can turn the dial to a lower range to get a better reading.

    • If you set the range too low, the multimeter simply reads 1 or OL, indicating that it is overloaded or out of range. This won't hurt the multimeter, but we need to set the dial to a higher range.

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With the range set correctly, we get a reading of 9.42 volts. Reversing the probes won't do any harm; it just gives us a negative reading.
  • With the range set correctly, we get a reading of 9.42 volts.

  • Reversing the probes won't do any harm; it just gives us a negative reading.

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To begin, make sure no current is running through the circuit or component you want to test. Switch it off, unplug it from the wall, and remove any batteries. Remember that you'll be testing the resistance of the entire circuit. If you want to test an individual component such as a resistor, test it by itself—not with it soldered in place!
  • To begin, make sure no current is running through the circuit or component you want to test. Switch it off, unplug it from the wall, and remove any batteries.

    • Remember that you'll be testing the resistance of the entire circuit. If you want to test an individual component such as a resistor, test it by itself—not with it soldered in place!

  • Plug the black probe into the COM port on your multimeter.

  • Plug the red probe into the VΩmA port.

Add Comment

Switch on your multimeter, and set the dial to resistance mode. Resistance is measured in ohms, indicated by the Ω symbol.
  • Switch on your multimeter, and set the dial to resistance mode.

    • Resistance is measured in ohms, indicated by the Ω symbol.

  • Most multimeters are not autoranging, meaning you will need to set the correct range for the resistance you expect to measure. If you're not sure, start with the highest setting.

Add Comment

Place one probe at each end of the circuit or component you want to test. It doesn't matter which probe goes where; resistance is non-directional.
  • Place one probe at each end of the circuit or component you want to test.

    • It doesn't matter which probe goes where; resistance is non-directional.

  • If your multimeter reads close to zero, the range is set too high for a good measurement. Turn the dial to a lower setting.

  • If you set the range too low, the multimeter simply reads 1 or OL, indicating that it is overloaded or out of range. This won't hurt the multimeter, but we need to set the dial to a higher range.

    • The other possibility is that the circuit or component you are testing doesn't have continuity—that is, it has infinite resistance. A non continuous circuit will always read 1 or OL on a resistance test.

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With the multimeter set to a usable range, we get a reading of 1.04k ohms.
  • With the multimeter set to a usable range, we get a reading of 1.04k ohms.

Easy to understand for a none electrician. Good.

ctsatph - Reply

Good tutorial ! Why was measuring AC and diodes not included ?

Andrew Azariah - Reply

Very good why can't the manufacturer write these instructions thank you

Brian ottewill - Reply

Finish Line

526 other people completed this guide.

Jeff Suovanen

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74 Comments

EASy and helpful indeed

Trever Mazibuko - Reply

Thank you! Never find instructions so easy to follow.

kuruvar - Reply

Iwant to know hw to test caperstas

kapambwe sikazwe -

Great stuff!! Thank you.

warwick - Reply

Super guide, many thanks for posting!

Alan - Reply

Thank you. Very easy and good training

Badar Omar - Reply

Very helpful for beginners, thanks for these clear instructions!

AndyBlaser - Reply

great article. thanks

James Magenga - Reply

thank you !!! for this info!!!

Sufian Hamouda - Reply

i did not know i can do this.

jeez - Reply

Thanks a lot this is very clear and helpful!

dillinger0893 - Reply

Thanks Jeff. I just purchased a cheap mm. All instructions were in Chinese. Your help made sense of it all, so easy.

David Bennet - Reply

Iwant to knw hw to test power suply

kapambwe sikazwe - Reply

great, thank you for good description.

hzaim2001 - Reply

Brilliant thank you

Liam Breen - Reply

It takes an intelligent person to write simple instructions. BRAVO !

dave - Reply

It truly does.

Shane Blanchett -

so nice Bro...Thanks a lot...

akramul haque apollo - Reply

Love the resources on the Pro site.

Shane Blanchett - Reply

Very good instructions

Md Kamruzzaman - Reply

Nice guide.pl add some additional examples to have better understanding for beginners.Thank you

sugashankar - Reply

Nice guide. Pl add some additional practical examples. Thank you.

sugashankar - Reply

I'm doing exactly this and mine won't read any voltages, but it will read resistance. I've tested it with multiple batteries that I know work, but I only get a read of 0. What might be the problem?

Juan Partida - Reply

Very good lesson, helped a lot. Thankyou

mark cole - Reply

This is the best and easiest lesson on using multimeter. Thanks a lot!

Seong Lee - Reply

Thank you, Haven't used one of these is ages; this was a great refresher!

GON Compactor - Reply

thanks for a very easy tutorial, it is very helpful!

bonjie montaflor - Reply

The basics. Soooo important. Well done, short and concise.

chris teter - Reply

Nice and straightforward guide - thanks buddy.

Mel Gavin - Reply

Most helpful thank you!

jodianderson34 - Reply

Had multimeter for a couple years, never knew how to make it beep!

Mike Weatherl - Reply

Thank you for these great instructions. The instructions that came with the multimeter were not helpful for a beginner, and these really helped us diagnose our problem.

Roger Lemaster - Reply

Thank you for the great instructions. My question and the reason for my looking online for info on using a multimeter was to find out what the various resistance readings mean on a digital tester. I am checking out a defrosting element in my refrigerator and got a reading of 12 or 15 ohms. The information I was reading said a 15-100 ohms meant the element was OK, another book said if medium resistance was found it was OK.

By going online I was looking for the answer as to what is low, medium and/or high resistance ranges are.

I did enjoy your instructions, they were easy to understand.

JM - Reply

I have used a meter for a long time. Never had instructions so clear and easy to follow. Thank you very much.

The pictures are also very clear and helpful.

Rick Lewis - Reply

Beautifully put. I truly appreciate the lesson. I've learned something of impirtance. Thank you.

rickeybenn - Reply

it really useful for begginer

erwin torres - Reply

Thanks you for the lesson :)

Mark Diamond - Reply

Hi,

das ist wirklich sehr anschaulich aufgebaut und benutzerfreundlich, vielen Dank dafür!

Wer jetzt noch genau wissen möchte wie Multimeter funktionieren und worauf Sie beim Kauf achten sollte der kann gerne noch auf https://multimeter-tester.de schauen und weiter lesen.

Ich wünsche euch noch einen schönen Abend und einen bestmöglichen Start ins neue Jahr.

LG

multimeter_tester - Reply

Thanks you for the lesson :)

mrmannan05 - Reply

A great introduction for a beginner like me.

Joe - Reply

Hello . and thank you good read.

conrad - Reply

Easy to understand...thank you

chip - Reply

Thanks and had help me a lot

sinoncesar - Reply

Had help me a lot. Many Thanks

sinoncesar - Reply

Thanks, I think I've got it.

rama jama - Reply

Simple and precise. A life saver as I couldn't find the "manual" - one page sheet. Greatful!

rudy2828 - Reply

Wow I love this I can now read a resistor thanks keep on the good work

Adeyefa - Reply

Great stuff this was helpful.

joel7269 - Reply

Thanks , sometimes need too refresh with the basics.

Kurt Webster - Reply

It is very nice demostration

Lokesha - Reply

Sir can i get a book about basics of auto electrical and electronics or soft copy.

Lokesha - Reply

Very informative! Easy to understand.

David Flatt - Reply

Well written.

Neville Amaral - Reply

Simple and easy thanks

kudakwashekatena - Reply

I have been searching a tutorial on getting started with trouble shooting an automotive parasitic draw. I have no background in different types of functions of a mmeter such as continuity, voltage, and resistance, your tutorial was a must have. It gave me an understanding of just the basic terminology of the more advanced tutorials. I give it a major thumbs up, excellent tutorial thanks a million !!!!!!

camotrucker87 - Reply

Easy to follow description. However, I am having trouble diagnosing a microwave diode. Seems I can't do that directly with a multimeter. Is that correct?

Rose - May 9, 2017

rakile - Reply

Thank you, the instructions that came with my multi meter were clear as mud. Your mini course was very clear and concise.

t_wellman - Reply

Thank you. This was very helpful to me. Very clear and easy to understand....

John Cascella - Reply

Thank you so much, it is so easy to understand the way you explain.

nodzgreat - Reply

thankyou very much.

keith - Reply

Thanks for supportive/useful post

Suman Ponmathan - Reply

Very Helpful.,thanks

Rey Mombay - Reply

Excellent please give us more of the same, primarily to help with understanding of the subject matter at a basic level.

mike payne - Reply

Excellent and elegantly simple guide.

Stewart Shackleton - Reply

Thanks you so much for this.For me as a beginner,I didn't find difficulties in reading this but its fruitful one.

Jhed Saldavia - Reply

thanks a million

claude.staples - Reply

It was just awsome.Before your tutorial it just was looked like some alien device to me and now I think it's having very simple working principle. I am now pretty confident to work with it. A very big thanks.

Biswarup Majumdar - Reply

Indeed awesome. Lots of thanks for such a generous sharing of knowledge. Be blessed

prince - Reply

very helpful,thanks

silvester - Reply

very simple and accurate

daniel - Reply

Awesome thanks.. I knew you could use this for a lot of things but not this much.

Lynn Comstock - Reply

I have a problem with my multimeter (Mastech MY74), the first thing I did was stupid, haven't read the user manual and tried it on a live socket and now it doesn't want to work. I have changed the fuses (600V, 0,4A and 10A), but it still doesn't work. Does anyone have an idea what else could have went wrong and how to test it?

Best regards

Rebius Noir - Reply

Very useful. I liked the statements like ‘this will not harm the multimeter but will show negative reading ‘. For non science folks like me, these questions crop up often so this guide takes away the anxieties.

Ninad Kajale - Reply

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