Hi Paul,
I much appreciate your input on this issue. I am exactly in the same situation. I bought the exact same alternator and have precisely the same problem. And, I have tested it as advised and it behaves exactly the same way.
So, thanks very much for your posts. I'll call OEX tomorrow, and hopefully they'll send me a new alternator as well, without any issues.
I agree, a $2,700 Lexus alternator when my Lexus is only worth 3-4k does not make any sense.
Cheers,
Peter