No Spark

I have a 1990 Ford e350 van with a 351 windsor. My battery died so I put my truck battery in to start it. I decided to put the old battery back in while it was running in order to charge it back up. As soon as I took the battery cable off, the motor stopped and hasnt started since. I replaced the coil and ignition module but am not getting any spark at the coil. I have voltage at both the coil and the ICM.

What else can I try? This is getting pathetic!!