Mk 1 focus zetec cylinder head temperature sensor?

[Nuttah]

My dad had a problem with his focus 1.6 zetec, the cooling fans were not kicking in, I noticed when i disconnected the wire to the cylinder head temperature sensor, the came on full speed. I am guessing the sensor could be the fault, according to eurocarparts,they sell 3 different sensor's, does anybody know if they all do the same job and are just different brands or are their actually different variants of the sensors?

[Dr Doofenshmirtz]

The cylinder head temp sensor also provides a signal to the dashboard temp gauge - so if the sender is faulty, you won't get a dash reading either.
Here's a link to one I purchased recently... http://www.ebay.co.uk/itm/Lemark-Coolant-Temperatu...

[S0 What]

The head sensor is for the ECU, if the ECU see no signal it will turn the fans on full as a safety measure, they also come on full when the ECU goes into LOS (limp mode).
Have a look on the stat housing see if there is a fan switch/sensor there? your fans may be operated by the ECU depending on the year IIRC