Ugh, we're the opposite...give me a mechanical troubleshoot over an electronic troubleshoot lol!

That fuse provides constant 12v to the fan at all times even with the ignition off. A third signal wire from the DME turns the fan on and varies speed.

But if the AC clutch was wired to that circuit it would be on all the time which may be the drain you are seeing. But key position would not affect this, it would be engaged all the time.

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04 X5 3.0i auto
03 X5 4.6is