I just wanted to post this so maybe it might help someone out in the future.
I did a search and could not find anything like this so hopefully this is new information.

2001 Grand Caravan Sport was due for a new battery.
I installed the new battery and cleaned up the cables and installed.
I then had a no start problem. Car would turn over but not start.
Sounded very funny. Lots of relays clicking. Sounded like a
computer problem. Worried that I somehow fryed it. Did the
on/off/on/off/on key thing and the only code was the just replaced
battery code. P something. Had a friend who is a mechanic who
has all of the good equipment stop over with a scanner and he found
no codes either. His scanner was able to take a snapshot of what is
happening in the computer while you try and start the van. The sensor
temps and a lot of various things made no sense. So I am thinking
new PCM?(computer). Last thing he mentioned before he left was
check the grounds.
I had already cleaned the cable ends, but the one extra smaller wire
on the ground I had not cleaned, since you had to remove the nut and
pull the bolt out. Turns out this smaller wire went straight to the frame.
I cleaned this up both at the battery end and the frame end.
For good measure, I cleaned up the smaller wire on the positive
side also.
Sure enough, problem fixed. Car runs perfect again.
So make sure to clean all wires ends on the battery connectors.
Hope this helps someone sometime......