From the factory e53 aux fan it's forward of the radiator.

Bumper cover must be removed but if you are willing to cut a little of the air ducting you can pull it out the top vs out the bottom (no need to loft car, might get away without removing the under belly skirt).

Foxwell scanner will command fan on to confirm fault also pulling the plug from the AC pressure sensor will engage the fan.

They are stupid pricey for OE and you have noticed that it's not entirely mission critical as you have a clutch driven fan also.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)