OK, I'm gong to think this through out-loud, so to speak.
I took the high beam light out of it's connection... When I stuck the tester in the connection one side was hot constantly. The other side would go dead when I would turn the high beams on.
So, on the PIAA wiring harness, out of the relay, there's the switch power wire and the black relay ground. I'm guessing that's the switch ground... Anyway, you're saying I wire the switch power into the wire that has constant power and the relay ground into the wire that goes out when I turn the high beams on?