[DeTomaso] Alternator Help

[Will Demelo]

Hi guys.
I’m hoping someone can help. Looks like SOBill may be out of town.
I originally had a 1 wire GM alt. All ran well but I had a drainage problem so I thought I would replace it. It was wired with 1 wire to the blue/blk wire that goes to the GEN lamp. I got another GM alternator and stupidly gave them my old one for core rebate.
I tried to wire it with 2 wires per drawing. It worked but was running on until I disconnected the blue/blk wire.
So I had it modified today to be a true 1 wire alt like my old one. Tied the #2 alt tab to the blue/blk wire . Alt is working but the car runs on. I disconnected the fans thinking I was getting a backfeed with no luck.
HELP!
Will