Can anyone shed any light ? Its basically since i bled the system through. The onboard computer says temps at 104 but still no fan cut in? when i unplug the left wireing on the rad(not sure that this is the temp switch or not) the fan cuts in most of the time, the relay is clicking on and off, but if i try to undo the header tank its boiling over? im lost any help is appreciated. I should probably mention my engine light is on and airbag light also not sure if these would effect anything. low speed fan comes on if i switch the car off after its been up in the 90 region but not whilst running?