My vehicle: 1995 chevy astro van, 163k mi, auto, 4.3lL engine. Vehicle has dead electrical system ; something happened while parked overnight; was running perfect, 14.2 V at idle, battery fully charged. Next day, NOTHING ! Battery reads o.O V. Have no schematic or diagram of fuse block. Could the problem be a main circuit breaker, I have no idea. Has only (1) fuse block, on driver side kick panel, very cramped. Please help, thank you.