Vent: I used to trash compressor testers until one saved my butt on a Friday call

3 years ago I thought those cheap $40 compressor testers were a gimmick. I always just checked ohms and called it good. Last month I got a no-cool call in Mesa, compressor showed fine on ohms, but the unit kept tripping on thermal. I borrowed a buddy's tester and it showed the start winding was shorting to ground only under load. Replaced the compressor, all good. Now I keep one in my van. Anyone else been burned by trusting just ohm readings?

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garcia.charles16d ago

I read a thread on HVAC-Talk where a guy had the exact same thing happen, a 5 ton Carrier that ohm'd out perfect cold but the windings would short once the compressor heated up and drew more amps. He said the issue only showed when he used a megohmmeter, which is basically what those testers do. I used to think they were overpriced junk too, but after hearing that and your story, i might just pick one up for the truck before summer hits.