Fans are fixed.
When I turn the AC on, the power to the compressor activates a relay that grounds the fans to kick them on, just like the ECM does. Ground the main fan relays and power goes to the fans. Simple. With both fans wired to the ecm's "fan high" wire, the ground wire from the AC could be tapped in to that wire to activate both fans at the same time. With one fan taken off of that circuit and connected to the ecm's "fan low" wire, it lost that ground signal from the AC. If I were to tee off the AC's ground wire to connect it to the fan that got moved to the low setting, I'd just be jumper wiring the fans back together. So I wired both of them to the low setting, they'll kick on at the same time, all the time, just like all my old fans. Except they will kick on at 202* now, rather than 210* like they used to. I feel like I should have had them set on the lower setting all along. I live in the desert, it's a heavy truck, it needs all the help it can get.
So everything is cool, literally. I even cleaned up a little bit of wiring on the drivers side inner fender where all the relays and stuff are located.
Looks like I'm going camping this weekend!