Hi all. The car is c220 cdi. 2008. About 30 seconds after starting the engine the fan cuts in and is quite noisy. I never used to hear it at all from inside the car but do now. It runs all the time until I stop the engine then it shuts down. There are no warning lights on. The temp is just under 90 where it has always been. The aircon may be not quite as cold. Coolant level is fine. I'm not good with electrical stuff so don't know where to start. Any help much appreciated.