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Testing Wico C & X mags with a multimeter?

Mike McKnight

Registered
All,
I'm trying to drag my dad into at least the late 20th century by giving him a multi-meter to help him test the components of the JD mags he likes to work on. Can anyone tell me what kind of readings he should be getting with his new meter on coils, condensers, etc?
Thanks,
Mike
 

mmcdonald

Sponsor
Last Subscription Date
04/13/2017
You didn't specify the meter but if its a Simpson 260 or similar, by setting it on 10000 ohm level and placing the leads on the condenser body and the wire lead you should see it charge(by needle movement) and go back to infinite. Swap leads and repeat, same result. I'm not sure at this instant whether this would work with a digital meter or all digital meters. I would think it would but because it's not dampened like an analog I'm not sure what you would actually see on the meter on a functioning capacitor. It would probably still show you a shorted one for sure not sure if it was open because of the fast reaction time. If you have no reading it's open or a constant reading it's shorted. That won't guarantee the condenser is ok as it's not an actual capacitance tester but it's normally a pretty good test. If you can check capacitance it should be right around .20 mfd on either one. With a coil a multimeter is less useful. While you can check to see if the winding's broken (no reading) and occasionally you can see shorted turns by the reading, more often and I mean WAY more often the winding's are intact but the insulation between them is deteriorated so that it shorts between turns when operating. You cannot test this with a multi-meter. Typically the primary will be around 1 ohm and the secondary around 7K. It can vary between coil manufacturers etc. so you can't really judge by this unless it's way off. You really need a coil tester to test a coil. The only other option is to run the coil in known good unit on a test stand or engine for sufficient amount of time and see that spark stays consistent throughout. Hope this helps.
 
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