T020 No Spark from coil to distributor

Peter Nelson · May 7, 2014

So I have this TO20 im fixing up that hasn't ran in years. I've converted it to a 12 volt negative ground, Replaced the coil. Got an electronic ignition. I'm 99% sure I wired it correct. I have another exact tractor that I rewired years ago to reference too. I'm reading roughly 9.85 volts going in and out of the coil, but no spark going to distributor. I did it in the dark.

When I measured the resistance of the coil from + to - I got 4.1 ohms. Ignition to - or + I measured 9.75 kilo ohms. I also made sure timing was O.K. Which I think it is. Did I get a vaulty coil. Maybe the Distributor is bad.(the only original part left)

mathman · May 7, 2014

Do you have a resistor in the wire going to the coil? And does the coil have an internal resistor?

rvirgil_KS · May 7, 2014

Not knowing the accuracy of the meter you are using 4.1 ohms from + to - is probably ok

9.75 K ohms from either + or - to the center output cavity of the coil would re reasonable

9.75K ohms from +or - to the ignition switch is way high....with that coil it should be near zero ohms.

According to Pertronix instructions that I have a Coil with 3 ohms or more primary resistance (+ to -) should not have extra resistor between coil + and ignition switch

T020 No Spark from coil to distributor

Peter Nelson

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mathman

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rvirgil_KS

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