mate. i dont know why the coolant was empty :O the mechanic who replaced the coolant sensor drained the system and put new coolant stuff in there (was well before november of last year i had that done)
i guess you have the melted fuse issue that plagues these car (
even though i never got that
)
if you open the engine bay and open the cover ontop of the battery there should be 3 fuses there. the one furthest on the right hand side is the fan fuse. this is a common
problem that SEAT know about yet did nothing.