1996 Dodge Ram Sport 4X4 No start No Communication

This truck is a recent purchase by my son. It ran fine for 2 months, recently the tranny stopped shifting into low gear and overdrive quit working as well. After looking at the truck I found that the tranny electrical connecter to the solenoids was unplugged. I plugged it back in and the truck ran fine for 2 days. My son was on his way home and the tranny quit down shifting into low (it would leave a stop in second gear) and when it shifted into overdrive he said the tranny shifted extremely hard. He pulled over to check the electrical plug. Shut the truck off, and now the fuel pump runs continuously and there is no spark to the ignition, I hooked up my OTC Genesis and have no communication. It was raining hard that day. I dried the tranny electrical connector with air and replaced the computer on the fire wall. The truck ran fine for 20 min. I went to back it out of the shop and it died with the same issue. ( Fuel pump on with key on and no communication)