[franken]

There are or seem to be a few problems.
1st, if the key on doesn't make key on stuff work, then does the key in the start (all the way right) not make a click or crank the starter?

The point is, you should look at this not from, it doesn't work, but from this part doesn't work. Break it down.

Do you have a horn or headlights?
Do you have dash lights or a radio?
Do you get a click or a grr when trying to start?

If it starts but won't shut off, I'd disconnect the big red wire at the alternator, and test. If it shuts off, that's a bit of wiring that isn't the problem.
The issue is related to switching power to the ignition off. Is this an HEI?

You need a voltmeter.

What's the voltage at the battery?
And so on.