radiator fan keeps running

:dontknow: cooling fan keeps going after i have switched off ,to stop it i have to take plug off the back of the fan is it the sensor at the bottom of the rad  

It should run on a little bit if it is hot, but no more than 30 secs really, yes time for a new temperature switch me thinks :-)

disconnect the plug from the sensor on the rad next time, if fan stops its the sensor, if it doesnt its something else.  some later models had rad fan after-run system fitted, if you follow the red/white wire see if there is a single pin spade connector going to it, if so, disconnect this to disable it.