Rcimp,
You are correct on the wiring location of the single wire unit. If you use a three wire unit, BATT will also connect to that ammeter location. #1 will connect to wire switched ON with the key and #2 can wrap right around at the alternator and hook into the big BATT lug.
Did the charging system work properly before. Your post indicates you had a externally regulated alternator running in conjunction with a regulator designed for a generator. This should not have worked. A generator is regulated by switching the field to ground...a alternator is regulated by switching field to voltage.
If you want reliability and ease of installation, a single wire is the ticket in my estimation.
Stuart
