black Mike's aftermarket coil how to determine + or -?

[emzdogz]

A few years ago when I was messing with this bike before and had it running ('80 SG project) I had purchased and mounted up one of the black MikesXS aftermarket coils for the stock elec ig. bikes.it looks just like this:

part # 17-6803 on his website.
Visually it looks just the same.
BUT! on mine the two leads are not marked + or -! there are no such markings on it. So how do I know which is which?
Also, apparently I'd had it hooked up before with a piece of ground wire to one of the mounting bolts.

Wondering if this rings a bell with anyone who'd bought one of these a few years back. Not sure if the current item is identical. It LOOKS just the same in the picture.

thanks!

 

[Sundie]

It's polarity insensitive. All dual tower coils are. One side goes to battery, the other goes to your ignition source (pamco, points, whatever, someone clapping), wire as convenient. Ignition source interrupts grounding to collapse the field and discharge the coils, thus creating spark.

 

[emzdogz]

It's polarity insensitive. All dual tower coils are. One side goes to battery, the other goes to your ignition source (pamco, points, whatever, someone clapping), wire as convenient. Ignition source interrupts grounding to collapse the field and discharge the coils, thus creating spark.

THANKS!!!!!!!!!!!

much appreciated....