Mini cooper S fan problems..

Anyone got any ideas? Right, the car has warranty... but im now doing the warranty work so need to sort this myself.. If im honest, me nor any other technician i have asked can solve it! I have asked master tech's. number 1 race tech's.. Im thinking its an earth problem maybe? Anyway.. The fan speed! As you can see in the video (excuse the ghetto focus and sun light) its climate control, it has 8 fan speeds.. When i set to to speed 1, it blows slowly, when i go to fan speed 2 it seems to go full whack! 3, 4, 5, 6, 7 and 8 dont change the speed at all, 1 is minimum, 2 is maximum it seems... When on speed 1, If i put any electrical load on, the fan speed raises to what sounds like full, the main one is when i turn the steering wheel. So if im parked, fan speed one. as im pulling out the space turning the wheel its on and off full speed! Headlights, high beam, brake lights etc all change the tone of the fan.. I did notice, If i rev too 3-4k, it doesnt do it as bad, which shouted bad battery/alternator to me.. but nope, there perfect!