I have finally fixed my overheating problem after 3 months lol First problem I had was no air con, no electric water pump and no radiator fan.... The fan module was replaced with no luck, more attention was shown towards the fuses on top of the battery which happen to be the problem, the air con and water pump were now working, sadly, the car still overheated / steamed out of the coolant cap if the air con was not on. Anyways, it did not bother me much as I always had the air con on, but with the drop in recent temperature, the air con no longer kicks in to prevent damage, which meant no fans! I bought a new engine coolant temp sensor, coolant cap and a radiator fan switch. Coolant cap and engine coolant temp sensor have now been changed, sadly the seller on eBay sent a 2 pin radiator fan switch which did not fit as the s3 has a triangular 3 pin radiator fan switch sensor, however replacing these 2 items fixed the problem (or maybe removing the radiator fan switch temporarily managed to shake loose some dirt). I would love to know how the above items work with each other, what controls what? Does anyone know? I also believe that my car may not of actually been overheating, my old coolant cap had no rubber seal, so this could have been why steam would come out of it, plus the lack of pressure would not help keep the boiling point higher than usual! All fixed now, but I would REALLY like to know about the 3 electrical components mentioned! Could someone also let me know what temp the fan should come on (both low and high speed).