Have been suffering from a lack of power from the turbo unit when the engine is warm. Replaced MAF sensor and spark plugs, having made sure the gap is correct according to the Haynes manual. Then I realised that the main fan was not working, d'oh!
Done some tests and currently have a connector to turn the fan on manually, but am at a loss to ascertain what has gone wrong, checked the fan speed 2 relay which is working and tested the voltages on the connectors and all seems okay.
I have also made sure that the air intake temperature sensor is connected.
As a note, the smaller air con fan is working just fine.

Any suggestions

Still have the same problem, can anyone tell me what the difference is suposed to be between to the inputs to the radiator fan please.
Basically one connection is to ground and the other 2 are to the 2 different relays in the engine bay fuse box, fan speed 1 and fan speed 2. Is there like a resistor across one of them to give lower speeds or something?
Any clues would be appreciated.

If anyone else should ever have this problem, there is a resistor in the fan of the turbo models. Basically it is to have two speeds, one in traffic and the other is for whizzing down the motorway/freeway.