How to test a Dual Run Capacitor from Air Conditioner with a Multimeter

A capacitor only passes AC and so will normally show an infinite resistance at DC. The technique shown in this video works because the initial application of the ohm meter hits the capacitor with a current transient (i.e., AC). The capacitor provides a relatively low resistance to this pulse of AC current, which is why the meter reading fluctuates before settling to the "infinite" resistance reading.

Here's a great test video

Thank you for sharing. I enjoyed the get to the point disclosure.

Mine was swelled up like a can of Popeye's spinach. 0.0 microfarads on both fan and compressor.

I died laughing at Herman Munster. Thanks for providing comic relief (and a great video) for my frustrating day

Thanks for educating the community and appreciate your volunteershi and also thanks to your team and your families

Please keep posting videos for every small maintenance step by step instructions so that community could do by them selves

Educating community is agreat service as Jesus Said

Will try it when I get mines today

NICE VIDEO!!
...should have shown discharging of the cap before the tests.....

😊😊😊 Thanks Dan .Your video was the only one I found that shows how to test with the OHMMETER. I verified I was doing it Wright.

Clutch video. Thank you for saving me some serious time and money.

Thank you 8 years later!

This does work for rudimentary testing. You do need to short the charge on the capacitor first. The longer the test meter ranges, it will show a relative charge capacity. I had the 45 side of a 45/5 capacitor go bad. Capacitance meter showed only .42 uF on the 45 uF side. The meter ranged about 11 seconds on the 5 uF side and barely 1 second on the 45 uF side. Bingo!

Great video. I wasn't getting any reading on the MF setting on my meter. This gave me another way to confirm the cap was toast

Uh, you set to ohms. That's resistance.

This is the best video ever. Short, quick and to the point. Thank you.

Why is it if I flip the probes I get a reading but if I do black to common I don’t?

thanks for the clear and short get to the point video, the one above yours guy keeps talking about a bunch of unnecessary things for 12 minutes before he attempts to get to the point

What does it mean when it goes to 58 ohms and stays there?

FYI, that's 2 million ohms, not 2,000.

You should explain your meter does not have a capacitance function and how you are using the AC function to test.

Ohms reading will NOT show negative if you reverse the leads.
A poor capacitor may show a decent value when out of circuit but fail under the working voltage when in circuit.
A new A/C capacitor for $10 or less is probably junk. There are imitation ones out there, they are an empty can with the wrong type of capacitor inside attached to the terminals. It will read an appropriate value when measured but will not function properly nor for very long. If the new one is substantially lighter weight than the original it is junk.
Testing if it is trash is fine. But if the unit is not open or shorted it may still be bad.

Thank you , thought I would have to get a 100 dollar multimeter to test.

HEY BRO WHAT IF IT JUMPS BUT JUST GOES BACK TO 0 NOT 1???

You made this video so simple
Absolutely brilliant and filled with integrity

Please when a capacitor test continuty is the capacitor okay?

Thank you! 👍

Thanks Dan…!!! Used this method to test my “bad” capacitor and saved some coin R&R’ing myself.

Perfect for laymen now I understand. Well done thankyou.

Easy to understand! You even used a multimeter that most people would have. Good job sir 👏👏👏

Digital po ba o analog ? Ano magnda gamitin? Kasi po bumalik pla pag capacitance.. pano mo makukuha ng analog actual exact na reading?

Dan the Man! a great explanation! Should a capacitor be oriented while in service so the terminals are at the top or can they be put in service laying on their side?

Mine jumps then goes right back to 1

I hope people watching your video realizes that this is not the correct way to check a compacitor.

This was exactly what my church needed to test and replace the capacitor! Thanks!!

Said nothing about the setting of the multimeter. what to puit the dial at

Thank you

Do I have to disconnect/remove the capacitor to check it with my newly purchased multimeter, please? Thx for the video.

so need to remove cap to check it? novice

Is it true that the shelf life of a capacitor is 2 years

Excellent info thanks

Thanks!!!!!!!

Thank you for the video. Tested mine and get no reading on herm or fan.
Odd thing is my fan will run but I'm the compressor is not coming on/no cooling. Is that even possible or am I misunderstanding?

Thanks! Mine didn’t jump from C to HERM or FAN.

This did not work for me. Both bad and new capacitors all showed "OL" when testing. Made me think new capacitor was bad. I went out & purchased new Klein meter that measures capacitors micro farads (sp?) which showed new capacitor as good (and proved old one was bad). Don't trust measuring ohms across these capacitors.

I don't have a professional multimeter like you do oh wait never mind I got the same one

Great video... short and to the point. Thanks!

This test only will show that the cap is open, won't show if it's failing (low uF). To test for a short test to the can/chassis. I noticed the meter he was using also had an actual cap testing setting (at 1 o'clock on the dial). probably should start there to actually test the uF. Then show the ohm method for meters that don't have the cap test setting.

Do I need to discharge the capacitor

simple easy to understand and not 20 minutes of talking and 30 seconds of testing. Thank you.