Got in the car this morning , all iced up so i turn the fan up full with it in demist mode then got out and scraped the ice off.... when i got back in the car even though the blower is set to full when i pull on the windscreen wiper to do it's double sweep the blower speed increased significantly even though it was still set on full .... it only does it whilst the wipers are in double sweep mode when you pull on the windscreen wiper stalk and slows back down a bit once it's finished, it dosn't do it when the wipers are on normal.... it's not some sort of feature is it ??? i'm more inclined to think i've got a dogy earth somewhere but have no idea where to look... it's not really an issue for me but if it's the start of a bigger problem then i would like to know