lost on a accel dissy

[recklessnova]

ok hear goes im loosing my mind
chevy 350
accel 5100 dis crane ps60 coil taylor wires
12.44 volts at the coil battery direct to the + brown wire hooked up to the neg side of it
dis has same voltage as the coil to the red wire and it has a good ground
during cranking the neg side of the coil goes from 12.44 volts to 6 something like the dis is telling it what to do and ive tried two coil wires
is there a way to check spark from the coil with out burning up my meter i tried a spark plug grounded but that dosent seem to work still no spark anyone with any information that might help would be awsome im about two steps from throwing in the hei something i dont want to do one is the size and the other is it lets oil up into the top (knock off hei)
thanks a bunch guys
josh

[recklessnova]

ok well i fidgured out the problem i think anyway i put in a mallory box and got rid of the module and just used the mag pickup works great ran it around last night only problem is with the vac advance hooked up to the dizzy it back fires out the exhaust but with it disconnected and caped off it runs fine it has a adjustable vac can on the dizzy and im guessing its just advancing the timing to far
josh