12 volt ignition

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12 volt ignition


Post by shovpan » Sat Apr 21, 2012 6:57 pm

I converted the panhead to a 12 volt system and want to check what I was told way back then. The new coil gives me these readings; over +/- posts 3.6 ohms, over the plug wire posts 10,300 ohms, over the plug wire to + or - posts is open. These good readings? I think I need a ballast resistor also. What rating should it be and should it be placed between the ignition switch and coil or between the coil and points/timer? Tia shovpan.

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Re: 12 volt ignition


Post by 1950Panhead » Sat Apr 21, 2012 7:48 pm

Most 3 ohm or 3+ ohm coils are designed to run on 12 volts.
1.0, 1.5, 2.0 ohm coils (12 volt) need a ballast resistor.
In 50's or early 60's Chevrolet when the starter is cranking the coil gets 12 volts to produce a hotter spark, when running the ballast resistor is between the battery and the coil.

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