'93 Ford Tempo No Spark

I'm trying to help someone who is building my house for nothing and
his wife's car has died for the 3rd time in 6 months. First time I
fixed it by tapping on the magic black box with the end of a bic
lighter, that was after he tryed fixing it for a half hour and gave
up. The second time another person said it was the coil plug in and
was fixed once again.

I read the 2006 thread and couldn't come up with a consensus with the
coil voltage. This one shows 12 v on both sides, this to me says there
is no ground, but it has been a long time since I worked on coils.
Shouldn't the negative side read zero? It also shows about 9.25 v
across the two, but 12+ from the battery negative to each.

Can anyone give me some trouble shooting ideas and what the parts look
like and location? Must be something simple... He has and extra magic
box, coil, and a computer trouble shooter with the wrong plug in. His
has about 12 pins and needs about 5 at the EEG Test? If we can get a
converter will that help with this problem?