The problem is caused by the ECU fan switch on temperature being lower that the stat fully open temperature. It would be ok to up the fan switch on temperature, because the Duratec is designed to run at the higher temperature, but we can't because the ECU is locked, so the only option is to lower the stat temperature, which we can by fitting a part from Ford, Caterham Cars or Cosworths parts catalogs. Not quite the only option... you could add another sensor and control the fan from that. Or possibly use the temperature signal from the existing sensor to the ECU. Has anyone tested what's coming out of the two fan output connectors against temperature? Jonathan