Chevrolet Repair: complete electrical failure in 95 chevy astro van, chevy astro van, side kick panel

Question
my'95 chevy astro van has 163k mi.,auto,a/c,4.3L engine,van & powertrain in v.g.condition. after being parked overnight,completely dead electrical next day;"0" works.was running super,14+v at idle,battery fully charged.next day,0.0v off the battery.have no schematic or diagrahm of fuse block;only(1)block on driver side kick panel,none in engine compartment.main circuit breaker? i don't know.hope you can help. thanx

Answer
Did you try to jump start it. If you did were you able to get it running and charging at good amps. Not implying anything but did you leave anything on. I need to know if you got it running and if it did it again, what kind of amps was it charging at after getting it started