Petronix testing?

Here's the thing. If the unit is wired up with ballast in place, the Pertronix should hook up "before" the ballast. So if you run it with a jumper to coil + the module will then actually be running through the ballast at reduced voltage.

There's only two wires to these, and all the destructions are easy to find at Pertronix, so my advice is download em, read em and go from there.