OK I scanned 2 diagrams... but my scanner couldn't get the whole thing on one page, so you'll have to put them together or whatever.
schem1 & schem2 are the actual wiring diagram.
chart1 & chart2 are more a pictoral representation of the wiring.
you'll see that the plus side of the battery is connected to various things (starter, alternator, electronics module) even with the key in the off position. You'll have to figure out if any of those could be a problem, or possibly the keyswitch is bad, or you've got a wiring short.
Good luck.
Pete