Cooling fans always on ??

The cooling fans on my 06 Exige S have started to run constantly. The car is not overheating, the fan starts when I turn on the ignition and stops when I turn the car off. The car runs at a normal 88 - 92 deg C.

Any Ideas or anybody else had this problem ?

It seemed to start after washing the car so possibly shorted something out with water ??

Thanks

Is the aircon on?