Back after a long hiatus.. The 2003 E39 540 M has been chugging along... I should point out the car is rarely driven hard and has approx 50k km.. Never really abused the car has never had brakes done or even tires changed yet.. On the last drive last year the climate system failed to respond properly and then all of sudden died completely.. Any input on the fan speed control (when it was going wonky it just wouldn't respond - it ran 100% then died like a blown gate or something) would result in nothing.. No air at all.... BMW wanted $180 for the part.. Found at NAPA (made in china) for around $110.. You can get them on ebay (china) very cheap aswell..
The culprit as usual was the FSU.. It wasn't fun replacing and im skinny.. It is easily doable though..
Now to fix the other problems..