Coil problems maybe

[macawlover70]

Hey all, I drove my car to work and stopped at the store and when I came out it wouldn't start. I found I was not getting any spark from the coil so I checked and made sure I was getting power to it. I was. I put the test leads on the groung side of the coil though and it showed no power. So i thought "bad ground" so i hooked up a jumper to the ground side and it sparked. I tested the groung side and it show 12 volts. Should it be 12 volts on both side of the coil? I put the coil off my dads truck on and it did the same thing after I tried to start it. Maybe I have a short somehow and it fried it when I tried to start it on the second coil. It just seems wierd that both coils show the same problem." 12 volts on both sides. I'm confused. I checked all the wires to the ground side and they show no voltage and the coil show 12 volts on the ground side with no wires hooked up to the ground side. Any help on the subject would be appreciated. All wires look good , no shorts that I can see. new magnetic pickup if that matters.
robert

[So Cal Mark]

your test light should pulse when attached to the ground side of the coil with engine cranking. It could be a failed ign module causing your trouble

[macawlover70]

thanks mark

[ga.spyder]

I had the same symtoms,back a year ago.Mark suggested the control module to me.He was spot on!It had 'shorted' out somehow.Replaced with a $20 part(GM) from Oreillys,and its been fine since.