Ignition coil bench test?

First you cannot measure it. The pulse width will probably not display much AND MAY RUIN YOUR METER

Second you need a capacitor, if its the older "round" coil we all "used to use."

Don't leave it hooked to 12V for long

Wire it up 12V--------coil+--------coil---------coil neg------capacitor-----to ground

Now take a jumper wire and repeatedly touch from coil neg to ground. Every time you pull it off, a nice fat spark should happen at the tower

"Rig" a spark tester, or old plug at the tower to ground

THE COIL CAN IS NOT GROUND. "Ground" in this case is your battery NEG