In this reaction video, HVAC veteran Derek Cole watches a DIY tutorial on replacing an air‑conditioner start capacitor. Throughout the commentary, Cole repeatedly emphasizes safety: always verify power is off, measure amp draw, and discharge capacitors before handling. He critiques the presenter’s casual approach, warning that even seemingly simple tasks can cause injury or damage expensive equipment. The video walks through identifying a faulty capacitor, visual inspection signs (bulging, leaking, burnt terminals), and proper testing with a multimeter set to microfarads. Cole explains capacitor ratings (e.g., 45/5 µF) and the importance of matching the unit’s specifications, noting the presenter’s possible mismatch when installing a 35/5 µF part in a 45/5 µF circuit. The presenter also showcases a universal “Turbo 200” capacitor as a low‑cost, versatile alternative. Throughout, Cole advises viewers to consider hiring a trained professional despite potential cost savings, citing his 25‑year experience with DIY mishaps. The overall message balances technical instruction with a strong safety‑first stance.
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And supposedly the power is killed to the unit. Always, always verify that is the case. Get your amp draws, make sure you don't have any power coming to that unit. Another DIY video and my reaction. Do-it-yourself capacitors— what do I think? Well, you probably know what I think, but we're still going to watch the video together. And see what my points are.
So the first thing we want to do is make sure that the power is turned off. Most commonly you'll have a disconnect like this with either a little plastic plug that pulls out or you'll have a breaker. Whichever is the case, flip the breaker off or simply pull this out. You can set it on top or you can flip it upside down and it acts as a little storage spot in the upside down position. Next, we're going to remove this side panel.
Okay, just because you take out the disconnect and supposedly the power is killed to the unit, always, always verify that is the case. Get your amp draws, make sure you don't have any power coming to that unit.
Typically there's a little electric hazard thing here so you know which panel to remove.
Electrical hazard. He just said hazard. So this is something you should be careful with if you're not a trained professional. I know this video is about do-it-yourself. If you're not a trained professional, get a trained professional. Yes, you're saving maybe hundreds of dollars, but is it worth you getting injured or causing more problems with their system because it's done wrong? Get a pro, make sure it's done properly.
I'm going to be using my Klein multi-bit driver here. This is a great handheld tool because it has all of these different, um, sizes contained into one unit, and then if it's too long, you can also pop this out.
So being as I have small space So code is, uh, you want 18 inches or 2 feet of clearance around the unit, and as you can see there, that is not 2 feet.
Base here, I'm gonna actually use this without the handle to take it off on this side. You can find this tool in our Amazon store. Just go down to the link in the video description, click My Favorite HVAC tools, and you'll see all of these awesome tools that I use on a daily basis. All right, so we're going to take this front cover off. So right back here is the part that we are after. This is called the capacitor. Now the basic function of this capacitor is it acts like a little battery, and it gives the fan and the compressor a little jump, if you will, when they first start. Now, when these fail, there's a lot of signs that tell you that this has failed, and you don't even need a tool or anything to verify that the capacitor is bad. Now, before you touch anything, just observe this capacitor and see what the condition of that capacitor looks like. If it looks like this—
And how about you get the readings from the capacitor with your meter And you can see if it's bad or not versus guessing if it's bad or not. Just because it looks like it could be bad doesn't mean it's bad, but because it looks good doesn't mean it's good either. So double-check it with your meter, or even better, hire a professional.
Has a mushroomed out top or bottom, or is leaking fluid, or looks like it has burns, or has something caught in those terminals. It's safe to say that your capacitor is bad and that it needs to be replaced. But we will go into how to test your capacitor, even if it looks normal like this one. This one is actually bad, and we'll show you that with a voltmeter. Now, being as this acts as a battery, this unit will hold a charge sometimes, and so it's very important that when you take this capacitor out that you discharge the These lines by jumping a screwdriver or something between all of the leads, and that will effectively discharge this unit. Then you can go ahead and take it out. All right, so I'm going to show you exactly how I would do this, just so you know. First, I would just go ahead and arc these together while it's still attached to the unit, uh, just for a little bit of additional safety. And just FYI, I have never gotten popped Buy one of these, and for a long time—
Again, if you don't have any training, call a professional. There is no shame in getting it done by a professional. This is one of the most expensive appliances in your home. You don't want to risk your safety or what you could do to the unit if you make a mistake.
I did not discharge the capacitors But you, you know, you want to be as safe as possible, so take those little extra steps and you can avoid potential injuries. I've heard of some people getting popped by that even after the power is off. It's always a good idea to just snap a picture of this from multiple angles if you're not familiar with air conditioning and, and how this wiring works.
Now that it's free hanging, what we can do is we can go ahead and take off our So if you look at the capacitor, it's a, it's a 45/5 capacitor, which means 45 is on the compressor side to get that capacitor going and 5 is on the fan side.
Ground wire. Typically you'll only have one wire on the fan terminal there. That's obviously for your fan. Now I'm going to take my screwdriver And I'm gonna just jump these out. Let's go from this one to this one, just jump all 3 of these. So now if you had a normal AC unit, you wouldn't have these blue wires. So I'm gonna go ahead and take these off. These are for my hard start kit. I will have a separate video on what a hard start is and why it is beneficial to have on your system. So typically this is what you would see if you pulled off your capacitor. You'd have your brown wire there, so we'll remove that. We have one yellow that's on the hermetic pin there, so we're going to remove that. And then we have a purple and a red on the C for common, so we'll go ahead and remove that. So now this is a freestanding unit. We can see what the values are. Mine is a 45-5. We can kind of inspect this and we can actually test this with a multimeter to verify if this is good or bad. Okay, so we got our voltmeter. We're going to set it over to this setting here. It should be uF. That's for microfarads. So make sure that you have a voltmeter that measures microfarads if you want to do this test. You can get one for pretty cheap, um, and it's very easy to do. So we're just going to take one pin, we're going to put it on C, and then we're going to take one and we're going to put it on fan. As you can see, we've got 4.6, and if you remember this 5 right here, that is for the fan and 45 is for the compressor. So plus or minus 5%, so we're within that range at 4.6. Now we're going to go from common To hermetic, and as you can see, we have zero. Now, this is totally ironic and a coincidence, but my capacitor failed at the very end of summer last year, and so this is a bad capacitor, but it looks totally normal. So this is a perfectly good brand new capacitor. Now we're going to test this one just for giggles.
Okay, that was—he was pointing at—that's the thirty-five five. Capacitor.
So between C and fan, we've got 4.9, which is right where we want it. And between common to hermetic or compressor, we've got 35.3. So right—
Okay, so he's taking a 45/5, installing it 35/5. So does this unit call for a 35/5, or does it call for a 45? He said he replaced it last year. Did he replace it with the wrong capacitor? Oversized capacitor? It depends on what your unit needs. The install manual can help with that.
Right where we want it. So that's what you should measure if you have a voltmeter and you're testing your capacitor. Now, if you're unsure of what size capacitor your unit has and you don't want to take the COVID off to, to look all that up, there is a simple solution and something that is really handy, especially for an HVAC technician, but it could be very handy for a DIYer or a homeowner, and it's called the Turbo 200. Now this is basically a universal capacitor that has a bunch of different values, and this will work on basically any AC unit. So we have common right in the center, and then let's say our unit needed a 35-5 capacity. So we would take this jumper and we would go from 25 to 10, that— and we add those 2 values together, which create a 35. So then we would just attach the one wire that went to the 35 on the old capacitor to one of these pins, doesn't matter which one, and then the 5 would go to this pin for the fan. So you have options here. If you want to pick up one of these universal ones and keep it in your junk drawer That's a great way to go. But if you want to open up your unit and just see what the values are on your capacitor, you can get one of these for about $10. You can keep it in your junk drawer, and that way when it's blazing hot outside, you don't have to call an HVAC technician to come out and charge you probably $300 to replace a $10 part.
Hey, I totally get it. I understand the video. My advice is to always get a professional to mess with your HVAC system. Do not do it yourself. Yeah, you're saving a couple hundred— hundreds of dollars you're saving by doing it yourself, but what kind of damage could you do to that very expensive piece of equipment? And is it worth the give and take for you being possibly hurt or causing damage versus saving a few hundred? Again, up to you. Just my opinion after almost 25 years in the business. I've seen so many people do-it-yourself mess things up worse than what they're trying to fix. So be careful, be safe, get a professional to take care of you.
