Thread: Why a Resistor?
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Old 01-05-2026, 02:19 PM   #6
TomC750
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Default Re: Why a Resistor?

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Quote:
Originally Posted by JayChicago View Post
AI said:
"When starting, the resistor allows a higher voltage to reach the coil temporarily.
This provides a hotter spark for easier engine starting, which is crucial in older vehicles."

I don't get this statement. (I know this is AI generated, which often gets bum info when it searches the internet) Is there any truth to this as it applies to our cars?

Many later cars did work this way. A 12 volt to 8 volt ballast resistor was bypassed during cranking.

But on our cars, the resistor is always in the circuit. I have measured the voltage reduction as the resistor gets hot, is only a few tenths of a volt. So don't see how, on our cars, the resistor helps start-up. Am I missing something about how a resistor functions?
I have witnessed the same thing, very little voltage reduction when resistor is hot. My car starts quite well, but I am inclined to bypass the resistor via the solenoid connection and diode route.
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