How to Use a Multimeter for Appliance Repair

I have this problem with my appliance. I've gone in and bought these parts to buy it and it didn't solve the problem to the unit. And then I'll ask them how do you know that was what was actually wrong with the unit? Did you test it with a multimeter? And more often than not, they say, well, I don't own a multimeter, but I just found that since your video showed you replacing this after testing it, I may as well replace it, and very often we find that the part wasn't really bad. They've gone out. They spent money. Maybe they end up returning the parts, screwing the business over.

How to Use a Multimeter at Your Desk

So I wanted to show you how to use a few different types and styles of meters at my desks. One fun thing about running a YouTube channel is everything's fake. I have this background behind me. I have this desk here with these meters, but the reality is there's a warehouse literally right behind my camera. Because there's a big warehouse, I'm going to go behind the camera and start buying a bunch of parts, And I want to show you how to test various things at my desk here and then we'll do some stuffplugged in, also. That's a little more dangerous and fun. So let's go ahead and startgrabbing some parts. I'm going to show you how to use some meters. Okay, now that I have all my tools and a bunch of meters, let's go over what a multimeter does.

A Multimeter Tests Electrical Signals Between Two Points

A multimeter simply Allows you to test the electrical signal between two points and figure if an electrical signal can happen or not. That's at least the easiest way that I could explain it. This is my first multimeter I've ever bought, and it's lasted six years, and it cost about 30 bucks, and it'slasted all this time using it for all these years. It's not a very large investment, but there's all kinds of different modes. The big one you're going to typically use is this one here that shows you like a little, almost like a Wi-Fi signal or something like this arrow you can see on the second camera.
This is for your continuity, and all you're doing generally when you use this is you're taking your electrical whatever and seeing if you can get a signal from point a to point b. You put your leads in which it will be of different sizes and seeing if it changes on your digital readout or your analog readout, or, in the case of something somewhat moderate, a tone that sound means that yes, you can get an electrical signal from one lead to the other.
Now, if whatever part is theoretically broken, then it's not going to get a signal unless the resistance is like super high and we'll get those in minute. And we're going to start with continuity, which is the probably the most prolific one you're ever going to use. So let's get to testing of quite a few real-world things that I have over here to the side.

I have a samsung thermal fuse here for a refrigerator. This is a thermal fuse that would stop working altogether if your refrigerator overheated, and if it overheated it's a safety feature to ensure that your refrigerator doesn't catch on fire or blow up. But if it pops, you're not going to get a signal now on something like this. It's outside of the refrigerator. You have the connection that would go in here to do, and this is your tip is that if you don't think the leads are going to fit in the front, fit them in the rear, like remembering my wife of that sometimes too. So you'll take your leads. You'll put them in on the rear side where the metal connections are, and you, , we should at least think we should- get a set. We will get a signal now to beeping, and depending on the device, the continuity setting also acts as resistance, and we'll get a number here.

Multimeters – What You Need to Know

usually, on most things, that number, if it's a sensor, is really a really low number. Some specialty sensors have a high number. Other sensors will have a variable number and that just depends on what you're trying to achieve. Different sensors have different reasons for existing. This is a pass or fail sensor meaning. If they can pass electric through, everything's fine. If it fails because something bad has happened, it's just not going to work, and you need to find the proper place. This and then find the problem. But without the multimeter you would know that this was actually a problem at all.

We don't sell a lot of these, but when we do sell them, it's because someone finally found this was the part that was broken. You could go in and replace the freezer or a bunch of different things, and this be the only thing that's wrong. Another really big one that people test a lot are heating elements, and I have a gigantic Samsung heating element here, and elements are definitely one of the biggest problems, because often people go in to replace everything, which can be very expensive, when it could just be one thing. And we have here a gigantic Samsung element. It has two sensors on it and then two speed connectors for the heating element.
So what we're going to do is go through, test these–and these are very simple but very common–to have certain things fail on them. And let's use this multimeter on these types of units. You have the sensors that will run on continuity and then the heating wire that's going to run off continuity and a resistance rating. Another thing to always do is, when you're testing and you're actually in a unit, make sure that at least one of the spade terminals is off, because otherwise you don't want the signal to get back Fed into another area on the device.

You only want to test what's right here. This one should give us a reading somewhere of 0.00, but it won't be. Oh well, Well, means that there's an open line which you know it's not getting a connection right now. This very second, meaning that there's something impeding a signal, and there we get 0.01 so that one's good, and then come over here.
This won't get back fed, since it's all isolated by itself and you have 0.0 there, and then we're going to go over to the element itself and we should get. We're getting 11–11 ohms or resistance there, which is about what you want. A heater element like this would get about 10 to 20 and the idea is, if there's a coil on the inside of this that somehow broken, then you're not going to get a signal through the multimeter somewhere on the inside. Theoretically, maybe a coil could be broken, and if that's the case, then it would show up on the multimeter that is actually broken. I would take my wire strippers and cut it just to demonstrate, but this is like a $70 element.

Break It Real Quick!

I don't ask, let's go ahead and break it real quick. Let's remember that I love you guys. So here's what we're going to do. We got a signal on this. We got some amperage. I'm going to go ahead and take my wire clippers and I'm going to go ahead and do it.

Rip it from this side. Hope you guys can see this. I'mdestroying an element on camera. I'm going cry afterwards, but you can see it. Got this wire here. I'm going to go and clip it.

Breaking the End Canal Wire

So we've broken the end canal wire. It is not working anymore. YouTube pays me a fee to do some of these videos, so there's going to be tons of listings for all these multimeters, and if you need any of these things, please check out the shopping page. But you can see that the wire is now totally shot on the inside. It's totallylocated, like if something happened, that it melt, and again we have an open line here. We should continue to get an open line now that the internal element has been severed, and we are, obviously, getting nothing zero.
There's an O l Meaning that there's no connection now. One reason I did sever this that I wanted to show you is sometimes you can get a rare instance on these heating elements to where the wire has disconnected.

On the inside it's broken, but it's not. Instead of it touching the wire, it's touching the element itself and it comes into what you'd call a grounding situation. Let's take this wire. I'm going to bend it against the chassis on the inside. Okay, so the wire on the inside is now bending and it's actually touching the cabinet. There's an electrical connection now between the wire going to the cabinet.

What Happens When You Touch The Spade Connector?

What happens? I kind of know what will happen. I kind of don't, so we're going to go back here, test the leads. What happens? Oh well, now we're not getting a signal from the wire from this side of the wire to this side of the wire, also. The harnesses won't touch. But what we should be able to do is move and try to see if we can get a signal here on the spade connector, meaning one side's connect to the wire and then go to the cabinet of the heater can, and we should get a connection, or at least I think we should get a connection. Let's see.

Yep, there we go. Now we are getting a connection on the wire going from the wire harness to the cabinet itself. This would be a situation where the wires grounding out and this can be very, very dangerous. You can get heat running through the element even if it's not supposed to. It can cause the sensors to burn out as a safety switch. You'd only figure this out if you physically looked at it or test it with a multimeter. So again we've grounded out the wire on the inside and we were able to get a connection when we touched the Spade terminal to the cabinet, but we weren't able to get a connection touching Spade to Spade on the multimeter. So that's a very dangerous situation.

Why You Want a Multimeter

On why you want to have a multimeter, you know if you replace the unit, you'd be okay, but what if you just went in and replace the sensors when you needed to replace the element, and vice versa? Often people will buy the heating element when it's just the sensors, and the sensors may be all of $25 dollars, whereas the whole heater canister could be anywhere from 70 to 150 om. And it's not a matter of trying to make you pay a lot more money for the multimeter. It will end up saving you a lot of money very often.

The Importance of Resistance in a Drain Pump

Now let's go to something else real quick. those were tests that you would just use for continuity with and without the alarm. The other thing that you want to look out for is resistance. If you're running something, let's say with a motor, not only does do you need to have continuity, it needs to have a certain resistance telling you that the coil is wound properly. And if the resistance is too high or too low, it's considered what we call house spec, and chances are it's not going to work properly. I have a brand new samsung drain pump here by ERP and it has two basic leads in it. Now I'm going to use my client–that's not my client–the co-130 that I stole all from Jeff this morning, and we're going to turn it to the horseshoe with the beep. I were going to see what the amperage is. clearly it's going to be a good value, but then it can vary from item item.

I think a drain pump like this should run about 60 ohms is about what I'm thinking it should, 13.8. If I'm, if I'm reading an upside down, it's about 13.8% which I'm going to assume is right. Sometimes numbers can change a little depending on how solid the connection is, and I have to check the spec on this to know. But I'm going to assume that's right because it is brand new from ERP. a lot of times the resistance matters a lot on a certain objects, especially sensors, like this. The big thing about sensors like this is you're passing voltage through it or current through it, depending on how hot or cold this little plastic pieces, the metal in it, expands and contracts, changes the resistance in it, and then the computer uses that information to decide if it's too warm, too cold or just right. Let's put our leads in the rear. So right around we're getting right around 5,000 ohms, which is exactly what you want.

Samsung Defrost Sensor – What's the Secret?

on this kind of sensor. This is a nearly universal defrost sensor from Samsung. The secret is GE–I think LG–and some other companies use the same sensor, and what happens is, as the temperature changes around us and it changes on the sensor, this number will go up and down, and that's how it knows exactly what the temperature is. You could put this in some ice, cold water, and it would increase significantly. You put it in your hand. My hand is warmer than the air around us, and that number is going to keep dropping and dropping, and dropping and dropping.

and what happens here is if the sensor is considered off-spec because it's going bad, the metal iscorroding or damaging, or something's wrong with it. What's going to happen is, instead of it being, say, 30 degrees on the inside and it needs to keep running the heater to defrost the ice andrip it off. What if it's off-spec and it thinks that it's 80 degrees and it can't run because there's a safety danger? Well, then you wouldn't get that defrost and you have a big ball of ice, and it would be a huge problem. And that's why you would have to check and make sure that this is on spec. And if you're smart about this, like a technician would, you would test these things from the control board on the back of the unit, wherever all the wires come in and go out at, instead of inside the unit taking the cabinet off.

Samsung Dryers – Is It Too Hot?

But we have all these parts here by themselves that we can test individually. Samsung dryers. Every brand dryer has a thermostat to it, and the thermostats on the dryers are identical. These two parts are identical. There's a very small, very, very small piece in it that is the bimetal strip, and this one should have a different value. It's not going to be based on 5000 ohms at temp, at normal temperature, at least I don't think so. It's 10,000 ohms. But the same principles are going to apply here.

This is inside the dryer and it's going to tell you if the dryer is too hot, just right, and it will send a signal wherever it needs to go. I'm going to place my finger on that bimetal and then it's going to rapidly, rapidly, rapidly drop, which sends the signal 8.0. It's warming. It's getting too hot, so it's dropped 1700 ohms in the process. I'm going to take my finger off. You laid a little bit and it's going to go back up. That up metal strip is going to get cooler and that number is going to drop. If I put my finger on it, it should get warmer and that number is going to go down.

Using a Multi-Meter to Test Live Voltage

And that's how all these sensors work. You think that they're some sort of really intelligent, smart, sciencey thing, but it's just a bit metal with some metalurgy and some science to it. That changes the values, and that's how things work, or they don't look right, depending on what's going on. Now in my studio I have this good working amana stove, but let's go up behind it and look at the electricity and some of the things that can happen. Some scenarios now, at the rear of working stove. The reason that you'd want to use your multi-meter and test live voltage is to make sure that the wire going to the plug going to thebreaker actually works, and if there isn't an issue here, you could go in and try to a work good working oven that doesn't heat because there's an issue somewhere starting here, going back.

How to Use a Multi-Messor to Get the Correct Voltage

What you would do is you take your multi-meter, switch it to the voltage AC, which is the little squiggly line, and rather than the straight line and dots, which is DC voltage, which is a lot for PCBs, and you would use your two leads to press them against the various posts to get your voltage. Now the big thing here is you absolutely want to use your leads, not your fingers, because if you touch your fingers, here you become part of the circuit, which is a really, really bad idea. So in something like this, you'd use your gloves and then you would use your Multi-meter and use the two leads to test the side posts, which should get 240 volts, and then the middle and left, middle and right, to ensure that there is the correct voltage. And at least in the us, these are the right numbers that you would want to have for a stove like this. If something happened that a line was bad, you may get 120 on one side but not on the other. And remember, voltage only shows you what the potential value is between two of the posts or the the lines.

How to Use a Multimeter

It doesn't show the actual current going through it at that time. It's only the potential, the amperage setting on this, which would be the 2 lash (2.0%) or the 200 lash (400%), that would test the actual electricity consumption or current going through it at any one given time, and that would be super helpful to see if there's an issue with igniter or other object. So let's go through and discuss that, also. The first example of using an amp clamp is for gas stoves that don't heat properly. It's possible that the igniter could glow and act like it works, but it actually does not. Underneath there's a safety valve and a warming drawer that operates the gas in tandem with an igniter. To use the amp clamp on something like this, you turn the multimeter to the a symbol and on the appliances it's always on the lowest range of amps, usually between two and 20 amps.

Next, you would turn the device on and see what themeter says. One key thing to note is the amp clamp only can go on one single wire. You can't, for example, put it on a power cord that has both a hot and a neutral, as they would cancel each other out. So the wires have to be absolutely separated, with only one inside the clamp itself. For example, on this gas stove, you need three amps for the valve to open to feed gas to the stove, because that's how much it takes to actually ignite natural gas or propane. Now, since it's not hitting three amps, it's going to glow and work, but it's not going to ignite because there's no gas going to the stove. Another example that you can use an amp clamp on Is for refrigerators with low freon.

If you can locate a single wire going to the compressor and put your multimeter on it, the Hotline will show you exactly how much work the compressor's motor is doing. The amperage needed to properly compress refrigeratorvaries from model to model, but generally the higher the better, and if you know the number, you can tell if the compressor's actually running internally properly, or it's not running enough telling you that there is a problem with refrigerator. These are all the ways you can use a multimeter. It's important that you have one and know how to use one. I hope these examples help you and give you some good ideas on how to use one.