Diagnosing & Repairing Multiple Electrical Failures on an Old R-22 Unit

Added: 2026-05-22

[00:00:01]It's a cat over there just watching me.

[00:00:15]Okay, it is Tuesday, May 20th, uh 9:55 p.m.

[00:00:22]Uh I finished my first job of the day, which was AC maintenance. Uh, I had a little bit of a later start on that because I had was on my way there, but then I had to turn around and take Gio back to the office to pick up some material for a job later.

[00:00:37]Uh, but that was straightforward just maintenance. Now I'm on the way to my second call, which is it's dispatched out as split AC unit needs freon, I believe is what it was written out as.

[00:00:52]I'm going to read it right now. need to add Freon for cooling.

[00:00:57]Uh it shows no customer history. It's possible a very long time ago before we used House Call Pro, we went there and it's just not recent, but um we'll see what happens if it's Freon or if it's Pureon. And uh hopefully it's not frozen when I get there. But uh they probably add refrigerant every year.

[00:01:21]That's probably why they think they need to add again, but we'll present them with all the options if that's the case.

[00:01:27]But we'll see what it is when we get there. Okay, so I'm at the uh outdoor unit.

[00:01:34]She turned it on. It didn't come on.

[00:01:37]I uh jumped the thermostat.

[00:01:40]Still didn't come on.

[00:01:43]I have been here before uh for home warranty repair. It was like AIG the home warranty company, but now they're just paying us as is. But going back up into the indoor unit, my meter, figure out what's going on.

[00:02:05]Okay, here's our access.

[00:02:14]Not a terrible attic.

[00:02:20]Not the best either.

[00:02:38]Okay.

[00:02:44]Try not to push this duct that I'm climbing over.

[00:02:56]Okay, let's see what we got.

[00:03:06]Let's get our voltmeter set up. The voltage leads are in all the way.

[00:03:18]Let's check.

[00:03:20]It's starting to get warm. Incoming power 249.

[00:03:25]Okay.

[00:03:28]Yeah, we got looks like some meltage, but let's go from R to uh the ground. Let's see. I'm going to get it right there. Should be okay.

[00:03:55]Two volts.

[00:03:57]So, looks like we have a dead transformer.

[00:04:02]I'm just going to make sure I get a really good connection onto that R and ground two volts. Let's see where common is from our transformer.

[00:04:16]It is just grounded right there.

[00:04:19]But let's check from R to common.

[00:04:29]It is hot.

[00:04:40]I'm coming.

[00:04:45]Okay.

[00:04:46]There to there. We do not have 24 volts.

[00:04:50]We have a dead 24V transformer here.

[00:04:59]So, it's going to be a transformer at a minimum.

[00:05:03]And then I guess we'll see what our pressures are. She said the system was running a couple weeks ago, just wasn't cooling.

[00:05:10]But, uh, let's see. Where are the wires that go to our condenser?

[00:05:18]It's going to be these right here.

[00:05:25]Let's see.

[00:05:29]No. Wait, really?

[00:05:33]How did they do this?

[00:05:40]Thermostat is right here.

[00:05:46]And What do we got? Just uh red and white.

[00:05:57]Interesting that they uh exposed some wire here, but I do want to check.

[00:06:06]Wish I could check outside, but I could check here as well.

[00:06:13]resistance on contacttor coil outside.

[00:06:21]So this is either side of our coil.

[00:06:25]Oh yeah, we got we got Come on. Get a good connection there.

[00:06:35]One ohm.

[00:06:37]So it looks like we had a shorted contactor.

[00:06:43]below our transformer.

[00:06:51]Let's get these back on there.

[00:07:00]Let's cover this one up.

[00:07:06]And what I'm going to do here, fold that wire just like that.

[00:07:12]and throw a wire nut on it so that that's covered because I don't want that exposed.

[00:07:21]But it is nice to have it to test.

[00:07:26]So, I'm going to be double sure. Now, I did get like uh I think twoish ohms. It was kind of hard to get a good reading, but I'll double check get that contacttor outside. Check the resistance there. Uh, but it looks like it's going to be a dead transformer due to a bad contactor. So, at a minimum, we're gonna have to replace those two if that's the case.

[00:07:48]Okay, got my meter, got our contactor.

[00:07:54]Going to pull both leads off. Is possible we have a short in the wiring.

[00:08:00]Let's see here. No, we got zero ohms of resistance on our contacttor. So, we're uh dead contacttor.

[00:08:09]So, we'll let the customer know and see how they're going to proceed. Okay. So, I just went over everything with her.

[00:08:16]She's pretty certain that it's going to be low on refrigerant. Told her I'm not going to check the charge until I have the system running. It doesn't make sense. I can't tell her how low it's going to be. But, grab transformer. This is the one with the built-in circuit breaker and contactor.

[00:08:46]Get the contacttor swapped out. It's getting pretty warm already again.

[00:08:52]But I do like um do like the summertime.

[00:08:56]I hate the heat, but I like the work, boy.

[00:08:59]I'd rather be in the cold, but I'd rather work on AC units. That's why I've been recording more lately. It's because I just enjoy AC work and I could I mean, like I goes usually pretty smoothly.

[00:09:15]Like, it's not like I'm scratching my head all the time. I usually able to pretty quickly diagnose, so I don't mind pulling the camera out to uh record.

[00:09:26]Got my tool bag here.

[00:09:29]strippers, screwdriver.

[00:09:33]Let's pull our disconnect.

[00:09:38]Flip it over.

[00:09:40]Pop it in there.

[00:09:42]Let's take our voltmeter.

[00:09:45]Set it to voltage and confirm. Line to line. No power.

[00:09:55]From line to ground, no power. And from our other line to ground, no power. So, I'm not going to bore you with the details of removing all these wires, pulling out the contactor, and putting a new one in. That's pretty straightforward. Everything just goes exactly where it is now, but on the new contactctor.

[00:10:17]Okay. Got our old contactor out. Cut the wires cuz I'm not using these uh crimp connectors on the new one.

[00:10:25]You can see this one has a shunt. It only breaks one pole. It doesn't matter in this case.

[00:10:31]So, uh, we got our wires hooked up there now. And we got a double pole. So, it'll break both lines, which that, uh, that can matter in some instances if there's a crankase heater, I believe, for other things, but for this basic fan, compressor, and that's it. It's not needed. I'm just going to grab some screws and a few wiggos from the top before I go in the attic so I don't have to make any surprise trips. Then we'll get this transformer replaced.

[00:11:03]Okay, up to the attic I go.

[00:11:10]It's not too bad up here. I think it's worth out in the sun, but it's 86, so it's not like uh crazy crazy hot, but it's warm.

[00:11:22]And they got a big dog here that uh she said is not friendly. So, he's locked up, but that's always nerve-wracking.

[00:11:29]But time to go back back in. Okay, I got my new transformer in. Uh this is a multi- voltage transformer. Most are.

[00:11:41]So, we got uh choice between black and white, black and red, and black and orange. We have 240, not 208 here. So, orange and black are coming in right here to our power, which means our white and red wires are capped. Here's our white. Here's our red. And then our yellow is going to R. And our blue is going to come in here to uh complete that 24vt circuit. So, I'm just going to push this blower in. I had to pull it out a little to get to it and uh power it on. Okay, blower's in.

[00:12:18]Our thermostat is set to cooling. Power is on at the outdoor unit. Should be able to apply power and we kick right on. And then uh if there was a short or anything still, which I knew there wasn't cuz I tested continuity. But this uh circuit breaker would trip and pop.

[00:12:35]Transformer circuit would be opened instead of blowing the transformer. But let's get our cover door back on and check our pressures.

[00:12:45]It's a cat over there just watching me.

[00:12:54]But uh a lot of people comment, maybe not a lot, but a few people have been commenting to get an umbrella. I have an umbrella. I just don't pull it out all the time cuz it's uh a little bit of a pain to pull it out every single time. Just when it's really bad, I'll pull it out. It's really hot right now in the sun. So hopefully you can hear me.

[00:13:20]Very dusty over here. Condenser is very loud. It's an old R22 pain unit.

[00:13:29]Got to keep our caps out of the dirt.

[00:13:33]Of course, that one's on some tight.

[00:13:46]Okay.

[00:13:55]High side here on low side.

[00:14:20]our temperature clamps. Here's our suction.

[00:14:26]And here is our That's a big spider.

[00:14:30]Here's our liquid line.

[00:14:35]Then I will open up my application.

[00:15:07]Let's see. Measurements link tool.

[00:15:24]Uh, I got to update.

[00:15:32]This stinks.

[00:15:33]>> One eternity later.

[00:15:36]>> I don't want to wait for this to update.

[00:15:38]So, I'm just going to disconnect it and see what the temperature clamp reads here.

[00:15:46]100°. That gives us insane subcooling. 33° of sub cooling.

[00:16:00]So, Definitely not low on refrigerant.

[00:16:10]Anything we might be overcharged, but um spoils also not in the best shape. Doesn't look horribly dirty, but it's probably pretty plugged up with how hot this thing is discharging. But we'll see uh how they want to proceed from here. I'll let them know how the pressures are doing, what it looks like, and how they want me to proceed with everything.

[00:16:41]Okay. So, I let them know um she's going to see about scheduling a maintenance and a cleaning on the unit.

[00:16:52]Uh possibly signing up for the service agreement. But um crud on my face.

[00:16:59]But uh she has to discuss it with her brother uh because he I guess owns the house. So is what it is for now. The system's cooling. Not great. It's about 12° delta t. Um but uh it's definitely old. I told them they should budget for replacement as well cuz it's going to come at some point.

[00:17:25]But, uh, that's going to be it for this one. Uh, pretty easy service call.

[00:17:31]Actually had the same thing yesterday morning. Uh, transformer and a contacttor.

[00:17:37]But hopefully you enjoyed watching the video. Like the video if you liked it.

[00:17:42]Comment any advice or criticisms or feedback and subscribe. Thanks for watching.

[00:17:56]Good boy. Caesar. Caesar. Caesar.

[00:18:00]Caesar. Sit.

[00:18:02]Sit.

[00:18:04]Caesar.

[00:18:08]Caesar. Sit. Caesar. Sit.

[00:18:13]Sit.

[00:18:17]Come on. Do it. Sit. Good boy.