That separate relay on blower final stage voltage supply was on pre 9/98 models. After that the final stage gets continuous (Terminal 30) voltage. So that relay can easily be bypassed.

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E39 530dA -02 M-Sport Messing metallic
E53 X5 3.0dA -06 Sport Stratus grey
E70 X5 40d -12 M-Sport Space grey