Hey guys I've got an aux fan problem. About 10-15 seconds after I start the car the aux fan comes on builds up to a high speed and stays on constantly throughout my journey. When I turn the car off it stops straight away. I've a feeling I may have a faulty sensor/ switch somewhere but what checking of switches/sensors can I do at home and where are they located so I can narrow the fault down. I'd rather spend a few pound on a sensor and fit it myself than take it to a garage. I got the car from an independent dealer and the car is still under warranty with him but his mechanic doesn't seem to think there is anything wrong so I'm not keen on taking it back there yet until I can identify the problem. In fact they fitted a new hedgehog last week for my wonky climate control and he said the aux fan was linked to that which I know it isn't, so my faith in him isn't great. If it's a cheap, easy fix I'll just do it myself. Any help guys would be greatly appreciated.