I'd check the thermostatic switch in the bottom of the radiator. Undo the connection, switch on the ignition, bridge the wiring plug contacts with a piece of wire (keep your fingers out of the way of the fan blades!!!) and if the fan comes on you know that the thermostatic switch is at fault. Just replace it with a new one.
If it is not the switch you'll have to check fuses, relays etc. Also make sure the cooling fan itself isn't seized. But it is often just that switch that fails.
Let us know how you get on please.
ChicksFan, February 2011
