MG T-ABC

Is there a way of checking whether the coil I have is best suited for a positive earth car. Whilst bought from the Octagon and therefore I assume OK, reading other articles I note that most generic coils are for negative earth cars. I understand that it shouldn`t necessarily make to much difference but I thought I`d check.

All ignition coils are fundamentally the same. The only factor that suits them to either positive or negative earth vehicles is the markings on the cap. Regardless of which way the coil is connected it will still produce a spark at the plug, however the most efficient spark will depend on which way the connections are made

This article explains it more comprehensively and lucidly than I can. Although related to the MGA the data are true for any coil ignition car.

Thank you

The only thing is which sides the primary and secondary are connected to. Supposedly that's what makes it a coil intended for one polarity or the other. I've heard that you get a slight improvement if it's connected a certain way versus vehicle polarity but I don't have any science to back that claim up. Connecting it to your car should of course be done polarity correct for best performance.

Thank you Steve. Lots of interesting reading discovered on the net.