upgrading regulator

OK Gentlemen, here's where it seems to go bad. new alternator, new regulator (switched from single field to dual), added wire from second field to ballast run side (with IGN1, dark blue with laser). thought maybe with the bad results I had a bad battery, so I bought new. 700 CCA.
seem to have 'zero' drop from battery to black wire at alt (unhooked, 12.57/12.57).
turn key to 'run' position, has a .07 drop
12.48 at battery, w/key in 'run' position: 12.42 battery, 11.92 at run/IGN1 side of ballast
with those numbers, 10.73 at ballast 'start' side while cranking.

now, with engine running:
12.38 at battery (12.10 when fan kicks in), 12.30 at alternator, 12.10 at ballast, 9.8 at coil (9.56 w/fan running). respectively, the negative side of the coil goes from 4.75 to 2.9 w/fan.
red from starter relay was 12.29 at bulkhead, couldn't check black as I had to put a butt connector in place (bulkhead wouldn't hold clips, burnt). relay numbers stay solid with battery.
with old battery, the reading at battery while running was 12.16, and at alternator 12.10
I know the new parts could be bad, but this is the same problem I was having with the lower output single field alternator, but now that I have done all the work of changing out bad wires, cleaning again, it's worse.
new alternator is shows the individual test at shop at idle: 72, cruise: 85, top end: 108.
any help appreciated, in any shape or form. thanks again all

had to edit because of another check, here's what I found. @1500 rpms, checked negative terminal to alternator-zero, to block-zero, but when I went to the ground strap from engine to firewall-16 volts! now, the ECU is bolted to the firewall WITH the ground strap on it. is that a problem? should I change that? is that causing the problem? could the ECU unit be bad? because of this?
thanks again