Troubleshoot the air conditioning dual capacitor

A quick troubleshoot of the dual run capacitor used on air conditioner and heat pumps.
This video is part of the heating and cooling series of training videos made to accompany my websites: and to pass on what I have learned in many years of service and repair. If you have suggestions or comments they are welcome.
If you are a homeowner looking to repair your own appliance, understand that the voltages can be lethal, the fuels are highly flammable and high pressures are used. Know your limits.

16 Replies to “Troubleshoot the air conditioning dual capacitor”

  1. I can't understand why you didn't explain which terminals the
    leads go to when testing

  2. Gray furnace man – Great video but you did not cover the tolerance for these capacitors at all. The capacitor you tested had a allowance of +/-6%. Therefore for the FAN the value needs to fall between 4.7 and 5.3 microfarads and for the HERM it needs to fall between 42.3 and 47.7 microfarads. Your FAN reading was 4.58 (BAD) and the HERM was 44.1 (GOOD). So technically the capacitor is out of its FAN range (8.4%) and is bad. I would trust the Fluke reading (love mine) and consider a new capacitor in this instance. I believe I am covering this correctly but appreciate feedback. It might be worth continuing to use the capacitor until it fails outright. Thanks for the video. Enjoy them.

  3. Thank you ! My capacitor was shot. Found one locally.This got me up and running on a hot and humid weekend.

  4. Question for you! I see a lot of these caps that are rust or corrosion on the terminals. Ever both with dielectric grease, Vaseline jelly, etc on the terminals?

  5. good video closeups not like other videos. good explanations. love your approach to teaching

  6. Reasonably close? It has +- 06% THere is no deciaml so I don't know if it's .06%, 0.6%, or just 6%. Can you help me?

  7. Thanks for this video! I learn something new about air conditioning issues

  8. as always great video Gary!  If you in stall a cap that's underrated for the given condenser can that damage the unit or perhaps cause the unit to have a time delayed start up for the compressor?
    Today I had a call with 3 caps inside and after configuring to a run start I now wonder if the existing caps were wrong perhaps a HACK tech?  single phase residential 3 1/2 ton

  9. Question if the capacitor is 45uf how low would the number be on your meter for it to be bad and the same with the 5uf?

  10. Peace be with u GFM. nice video, let me tell you my problem.. i have ac "AKIRA". my ac has stoped working, then i ckecked it, i found out that one of the wire connected to capacitor was burnt and cousing the capacitor to damage as well,. then i replace the capacitor 25uF with 30uF, then it ran for some minutes, sudenly the compressor again stop working, what i did was i bought a new capacitor again 25uF and replace the 30uF, but then when in turn on the power the compressor still not working. please give me some idea how to fix it. thankz

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