Pertronix Wiring

[Carmods@aol.com]

I am hooking up my engine after replacement. I have a Pertronix in the 
distributor with a red and a black wire. I remember that the red wire goes to 
the plus side of the coil but, perhaps due to old age I have forgotten for 
sure where the black wire goes. I would assume that it goes to the minus but 
I try not to assume. Can someone help?

                                        John Logan