trying to find out what the ECU would say what was wrong with the car, and it said there was no communication with vehicle?

any thoughts?

 

I once had a 1992 Plymouth Acclaim. The alternator tested good and the battery was new.
living 3 mile from work it was my rarely driver. after doing a test draw on it I pulled all fuses and it still drawed over 0.08 of more at time while sitting still not running. I was told by AutoZone that the voltage regulator was not in the alternator But rather in the computer.
They also told me the computer was a dealer only item. But, rather than a couple grand on a dealer computer I opted for 10 dollar boat battery switch at Oreilleys

Not sure this info will help? but it may?

 

well...finished up the wiring for the new alternator conversion and still the same results...