1998 Chrysler Concorde fuel, but no fire

Electrical problem
1998 Chrysler Concorde

I have a 98 concorde, a week ago it simply would not start, the engine crankc fine until the battery runs down. I checked and do have plenty of pressure at fuel rail. I noticed that after swapping around the relays, radiator, asd, I probed the asd and it reads 12 volts only for a fraction of a second when you turn the key over to start position, but has no voltage while engine cranks. The speedomeoter, tach, door locks on same ca have worked intermittently for the last 30,000 miles, but car has run fine. Any ideas?