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Jack E/NJ · 09-27-2021, 08:26 PM

>>>So if the coil has 1.5 ohms resistance, and ballast resistor 2 ohms what would the current in amps be in 12V circuit ? How do I measure the voltage to see if I have 3.8 to 4.2 volts at the points ? Thank you.>>>

Ohm's law calculations
Points closed, engine not running = 0 volts at the ungrounded point, 3.6 amps.

Points open. engine not running = 12.6 volts at the ungrounded point, 0 amps.

Ohm's law conclusions
Ignition switch left on, engine not running = good chance of fried coil and dead battery. 8^)

09-27-2021, 08:26 PM	#10
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Variable coil ballast resistor >>>So if the coil has 1.5 ohms resistance, and ballast resistor 2 ohms what would the current in amps be in 12V circuit ? How do I measure the voltage to see if I have 3.8 to 4.2 volts at the points ? Thank you.>>> Ohm's law calculations Points closed, engine not running = 0 volts at the ungrounded point, 3.6 amps. Points open. engine not running = 12.6 volts at the ungrounded point, 0 amps. Ohm's law conclusions Ignition switch left on, engine not running = good chance of fried coil and dead battery. 8^)