Truck run fine at start up, then dies, weird computer readings. on 1990 Dodge W150

The truck run when first started, will idle for about 30 seconds and then dies. I have my Genisys hooked up and the coolant temp and air charge temp will go from normal to -198 degrees, the battery voltage will drop to 0 and the RPM will drop to 0 then they all go back to normal, then drop again. Have replaced the temp sensor, the hall effect in the dist and the O2 sensor. Have no idea, please help. It will start back up but I have to cycle the switch a couple of times then it will start and then die after a couple of seconds.

Asked by for the 1990 Dodge W150
Wiring to ECM or failing ECM.
Gremlins, gotta love'em..