thanks for the advice peeps.. i read somewhere on here today about a fan switch on the escos that switches at a cooler temp than norm and am wondering if i was given one of these and this may be causing the problem.. the switch in the dash was really only for an emergency if the fans did not cut in.. looks a bit shit with people in the car and each time i stop having to explain that the fans dont work on their own.. as to most people its just a shitty old g reg sierra.. even if it is one ive wasted thousands on..