98 no start

[KennyZ]

I have searched and am continuing to search for more info about this topic:
98 disco w/ 4.0, had problems keeping it running for more than a few seconds--replaced "stepper motor"... after it wanted to die when coming to a stop--tested and replaced alternator and battery, started right away...turned it off, went inside to get insurance verification, came back out to start and NOW: it doesn't even appear to engage the starter, as if it was left in drive or reverse.
Some suspicions I have: could it be the anti-theft system? (never had a remote). could it be a 'reset switch' under the passenger side of the dash on the firewall? (got past the glovebox, but everything looks the same to me)

So, yeah, this is my first post(since I don't have many answers), and I am not on here very often. Please be patient with me if you need more info!

[KennyZ]

(a little further back...) before the hard starts and short idles listed above, it did the 'racing' motor and what-have-you indicative(sp?) of the 'stepper motor' problem.

[KennyZ]

128,000 miles...