Cranks but won't start. Unplug ground at field spade on Alternator and it starts?

My thought is to test whether it relates to the Unlite's power feed by connecting the Unilite directly to the battery positive and then see if it will start. It can't be left like that because it will be powered with the key off.

Are you using a piggy back to make the power connection? Those are pretty conventient and make decent electrical contact.