Fan control module problem?

[Roy Tyler]

Hi

My x type 2.0 sovereign diesel has developed an intermittent fault which seems to point to the fan resistor being at fault but I'm unsure. 

On some occasions the fans stay on after the ignition is switched off, but they seem to come on at random while I'm driving, and at the same time I lose acceleration/power, and the temp gauge moves up from its usual position to about half way. The only way to stop the fans is to switch off engine restart and rev hard before switching off again, if you continue driving again everything is fine. 

I don't get any warning lights, the temp gauge works fine and as its a 2.0 ltr doesn't have a Map sensor. So I'm wondering if other members may be able to help me with the diagnosis.

Thanks 

Roy