OK, well I still haven't got mine working
What I did work out is that (on mine at least) under the that cover in front of the battery, the relay that controls the radiator fan is the big black one that is rated at 50amps. I pulled that out and tested it by running 12v over the 2 smaller terminals (on the relay itself!). When doing that, I could hear the relay clicking over, and the resistance across the 2 larger terminals drops to 0ohms - so that is all good. Next thing I did was jumper across where the two big terminals would normally plug in - the fan fired up, so I know that works.
Now I know that the temperature sensor, that is in the top of the thermostat housing, controls the temperature gauge, but I'm not sure if it drives the fan relay or if there is another sensor somewhere. Can anyone answer that one? My temperature gauge is working fine, until I unplug that sensor.
Lehane, you could probably test the temp sensor by checking the resistance while cold, and then hot - provided you have an ohm meter (bugger all at Maplan or the like). Unscrew it and test in some boiling water in the kitchen, if you want to impress the wife...
. Mine has 3 terminals, which I'm curious about.
Oh yeah, turning on the AC in mine doesn't make the fan come on.