A/C Idle solenoid?

[ChevyGuyNC]

72 Cheyenne Super, 350/350.

Apparently a prior owner did something creative with the wire for this. It runs from the switch to the fuse panel, into one of the unfused always on blades. So, essentially, it's always engaged, keeping the idle higher even if the AC isn't on. I'm guessing that wire should go to a different source, one that is tied to the A/C somehow.

I've searched and seen different wiring diagrams; maybe I'm just not seeing where it should go.

Thoughts?

Have to replace the AC Diverter box and heater core... oh joy. But at least from what I've seen, the AC heater core is easier to do, and can be done from inside.