1991 Plymouth Voyager Started This Usually Very Reliable Van Immediately Died

This sounds more like how bad connections commonly act. Use a test light or digital voltmeter and start right at the battery measuring the voltage. Move one probe at a time to the next place down the line until you find where the voltage is missing. This happened last year on my '88 Grand Caravan, naturally on the coldest and windiest day of winter, and it turned out to be the smaller negative battery wire rusted off where it attached to the body near the left strut tower. I wired on a temporary wire from the battery negative clamp to the wiper motor to get home.

Also check the under-hood fuse box. I can't remember the year they started using that but if you have a large fuse that's bolted in, and there's a smaller red positive battery wire bolted to it, check those nuts. They like to work loose.