Cooling Fans stuck on

Hi All,
The engine cooling fans on my 2001 1.8 petrol Freelander came on suddenly whilst I was driving along the motorway (it was a cool day, not 90 in the shade!) and now they just wont turn off! They run at full speed (very noisy) as soon as I switch the engine on. Everything else is fine, no overheating etc etc.
Any ideas??

Sounds a bit like my problem. Could be the Fan Controller ECU on the radiator has failed. If you can find one without having to buy the whole rad assy let me know