Coil Polarity

[katy]

Does the spark polarity checker shown in post #2 work on negative ground systems as well as positive ground systems?

[Tom Wesenberg]

Originally Posted by katy

Does the spark polarity checker shown in post #2 work on negative ground systems as well as positive ground systems?

Yes. It indicates the spark polarity, so battery polarity doesn't matter, and neither does battery voltage matter.

[2manycars]

I put a distributor on a model T I had some years go, and was thinking model A when I wired the coil. Model T has negative ground. After a few hours of spirited driving the car quit and the coil was too hot to touch. I let it cool and reversed the wires, and it ran fine thenceforth.