MTFCA Forum

In testing a coil, if the capacitor is failing will it draw more amperage or less amperage or not be noticable?

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By Chris Barker July 19, 2009
I have found similar results. I think that you have to separate the two properties of the capacitor.
A good one should have capacitance (microfarads), but infinite resistance (ohms).
If you have zero capacitance, the coil will not work, whatever the resistance.
If you have some leakage - but the resistance is still very high - several megohms, it will work as long as it also has capacitance. There will come a point where the resistance is so low that it stops the capacitor charging up when the points close.
I don't know what values to put on these properties, but if it works on the HCCT I suggest use it - but carry a spare because someday it will fail.
I have also encountered coils with modern capacitors that have failed (no microfarads).

I highly recommend getting a capacitor test instrument. They are available on line and are easy to use.
Even if you choose to have the coils professionally rebuilt, you will know when to sent them in.

Art Mirtes

See this site: https://www.electronicshub.org/how-to-test-a-capacitor/