Is Your A/C Unit About To Die? This Tool Doesn't Lie

Just happened to my neighbor. Bad Cap caused unit Fan to stop working. Compressor goes into Thermal lock. He calls the AC repair man. The AC man tells him the Compressor is shot and that he needed a whole new systen at $22k.... I told him to wait for the motor to cool down and we replaced the Cap. All is working well now.

You want to pull ALL your wires off first, then test. There's a chance that the MEGGER could be checking windings all the way back in your system. Even if the wires are disconnected on the other end, you don't want to be checking the insulation against wires hanging out of the compressor. Also, it's best to sand back the copper pipe on the compressor and use that as your ground.

Residential and Light Commercial HVAC guy here. Diagnosing a bad compressor is the VERY last thing for me because checking capacitors and contactors is just so easy. For only $90, that tool isn't a bad thing to have anyway. It's so easy to be honest. I'd rather be wrong than crooked. Get 3 opinions ANYWAY. Good video.

You are the "Man." You are demystifying the ownership of a home a/c system. Thank you for your efforts!

I had THREE different ac companies tell me my 10-year-old compressor was shot and I needed a new system. Finally a friend of a friend came and looked at it and fixed it for less than $100 by simply replacing pressure switch. That was 10 years ago and it's still running fine today. Anyone else would have just believed them and paid for new system, especially after three different companies saying need new system. AC companies are worse than used car dealers!

The manual for the insulation tester recommends that all leads be removed from the compressor at time of test. I would think that in some cases this could be important as other components still in the circuit could cause the lower 100 mega ohm reading you saw on the Goodman. The little tester does seem like a good idea. The manual says it applies 500 volts to the circuit at very low current and this is what is needed to properly do a test like this. Thanks for your video.

I did my first job in 82. Sent the wife for a 6 pack of beer and it was WARM. She said the little store down the street had the cooler go out. I had just graduated the Weat Side Institute of Technology for A/C but the owner told me not to bother 2 different companies condemned the compressor... It was a sticky current start relay

I had an AC guy about 12 years ago tell me my unit sounded tired and it was probably time for a new one. Still running great after 12 years.

I put in several Fedders units back in the early 80's. It had a Rotary compressor back then. Didn't have scroll compressors then. The Rotary compressor lasted a long time in AC's with short line sets, but did not last very long in heat pumps with long line sets. The rotary compressor always had troubles oiling correctly. You were just lucky with the unit in this video. I quit selling Fedders very quickly because of their compressor failures. I went to selling Rheem in the early 70's and they were great systems, but they didn;t have heat pumps at that time, so that is the reason I tried Fedders. When Rheem came out with heat pumps, I never looked at a Fedders again, I was an Air Conditioning contractor from 1972 till 2016 and then retired.

Bad motor windings (checked with this meter) are only one of many things that can fail in a compressor. This only tells you if the insulation in the motor is good or not.

I know of one Lennox combo outdoor unit ( Air conditioner/ natural gas heat ) that is 35 years old and still working. My late father-in-law purchased the unit 35 years ago. He died in 2022 and a grandson purchased the house. The grandson had the unit serviced, ( coils cleaned, Freon checked, etc. ) that old Lennox unit is still working to this day. The newer units just do not last that long. I have purchased several AC, Heat pumps, over the years. I have three Lennox AC units that are 23 years old. I have purchased York, Trane, American Standard, and Heil units in the past for different houses. My latest purchase was a Heil Heat pump, three years ago. So far so good on it. Only got 13 years out of a 5 ton Trane Heat pump. Replaced the outdoor unit with an American Standard unit in 2017. So far so good on it. I don’t know which units are better than others, but a good HVAC guy makes a big difference. My experience has been that Lone Ranger type HVAC guys, or an HVAC guy who has one helper provide better results than HVAC technicians who work for large companies, who employ dozens of technicians. Those companies have to meet huge payrolls, whereas the one or two person HVAC company is under a lot less financial stress to meet payroll. A good HVAC person does not have to advertise to get all the business they can handle. I found a great HVAC guy back in 2003. He was just starting out on his own back then. I have since used him for all my new installs and all repairs. I told all my friends about him. He got so busy he had to hire a full-time helper. He has so much business, he can pick and choose his customers. He is honest, reliable, and always does excellent work. He never had to use paid advertising. Word of mouth is more powerful in growing a business than any type paid advertising.

As long as compressor is functional, all three windings are connected internally. Testing terminal by terminal as shown is also testing whatever is connected on the other two terminals and then some. All three wires need to be removed and just testing one terminal to ground will test all windings. That tester is low current, but puts out 500VDC. So if there is something at the end of one of the still connected wires that can be damaged by high voltage, you just damaged it. Or if a fan motor is connected at the contactor with the compressor, you are also testing that fan motor and wiring. Which, if you get a bad reading and mis-diagnose the compressor bad, when in fact it was the condenser fan or wiring, yeah..... Not to mention, there are other things that can indicate a failing compressor. Doing an insulation resistance test is just one test.

I helped a friends mother. He told me at work that it was the original unit to her home. When I got there it was a Chrysler Airtemp . Built in 1964. Had a bad contactor. Replaced, cleaned outdoor coil , lubricated outdoor condense fan, ,, STILL RUNNING TODAY.

I just updated my central heat & ac unit It was a Fedder installed in 1972. Replaced system not because the compressor failed but the ac system developed micro leaks. 3 in the last 4 years in different areas. With the insane cost of R-22 to recharge a 5 ton system. I couldn't justify the cost. So replaced the whole unit with the help of your videos. The $ saved on utilities and installing it myself. It will have paid for itself in 3.5 years. Thank You for the help. I could not have done it without your videos. Keep up the great work.

This is so awesome! I'm 55 years old and grew up hearing my grandparents say "They don't make things like they used to". Now, about 45 years later I'm hearing a younger guy say that same saying about current products. Love your videos. The facial hair addition is cool too! Keep it up!

I would completely isolate the compressor. And hook your ground to the component being tested. Testing like this it could be the compressor, the wires, the fan motor, the starting cap, or even the contactor.

I live in an rv park in Az. Many of these Park Models have been here since before 1982. Many of the rv's still have the original carrier pancake 2.5 ton straight cool ac with 7.5 kw heat strips and Coleman Saguaro park model, and you'd be surprised as to how many are still rocking. Performing very well I might add. Some have new fan motors but many are still factory, when I do a performance check the run caps are still spot on, and many haven't even been serviced in yrs, I do many a coil clean and install a tri-dem 3ply filter to keep their ducts clean for many yrs to come I will be getting a mega ohm to further prove to my customers that their unit is still good and performing as it should, not one of my service buddies has ever told me about a mega ohm meter before. Glad I came across your video in upping my knowledge

Love that silver YouTube plaque in the background,your videos are a great help for people who are overwhelmed by the hvac technology and of course some not too honest contractors

Proof that the stuff they make today is $hit. 30 years old and still good while a 5 year old system is on the way out. We need a car guy like this HVAC guy.

I have a 10 12 sheer Coleman heat pump and it is going on 27 years old and still running fine!