Well, as a follow up on my problem, I went through fuses and checking with ohmmeter. Finally got to the 25A (rear wiper motor, rear washer pump, rear wiper relay) in the box beside the battery to locate the one that had the issue.
I removed the fuse and put the battery back in, fired her up and let it run for a good spell to warm it all up. All seemed fine after a bit, so took daughter to work and then grabbed some take out to bring back home. The van had been running for a good 3/4 of an hour by now with no sign of trouble, so I turned it off to get the take-out food. Came back out and it barely turned over, but then caught and ran.
Now though, it was so low on power that all the lights in the cluster were flickering and fading out, it got worse if I accelerated. Limped it back home and checked the voltage across the battery with it running.
With all accesories off: 13.3 volts
lights and heater fan going: 11.5 volts (I did notice at stop lights before that the fan speed would reduce and then increase once stepped on gas when light went green)
I just replaced the alternator 2 yrs ago, but sure looks like its pooched again I guess and prolly ruined the battery as well for its been undercharging for quite some time now that I think about it. The fluctuation in heater fan speed has been going on since cold season started. Couldn't afford to fix alternator at the time...