pertronix question - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Nate58 · 06-12-2011, 17:33

when using a pertronix electronic ignition, do you leave the ballast resistor in place or bypass it?
the 352 in our 58 skyliner idles smooth, but sputters a bit when you raise the rpm. we have a cheap timing light, and it flashes steady at idle, but is a bit jumpy with the rpm increase. i'm not sure if the light is just incapable of flashing that quickly, or if perhaps it's showing a spark issue.

**jwko** · 06-12-2011, 17:52

Hope this info helps

Quote:

No, the idea of the resistor is that you deliberately design
the coil to operate at a voltage lower than 12 V and then use
the resistor to get to that voltage under normal conditions.
When you're cranking the engine with the starter the battery
voltage drops and hence the sparks get weaker. To combat this
you bypass the resistor as long as the starter is operating.
This gives you pretty much similar sparks during cranking and
normal operation. It doesn't matter if you're running
electronic or mechanical points, it works the same way for both.

Nate58 · 06-12-2011, 18:43

so, the ballast resistor should stay, because running without it is a good way to fry the coil....yes?

**jwko** · 06-12-2011, 19:21

No, I don't think it will hurt the coil. It just helps compensate for voltage drain and allow the coil to fire a full power during engine cranking.