Help with wire location on 1.8 16v

[big bird 0]

Having refitted the engine in a 1.8 16v after a long period since the engine was taken out, I can't work out where one wire connects. The black wire is on the drivers side and exits the wiring loom singularly between the air box and the inner wing. This single black wire has a female spade connector on it and it is not particularly long. If I ground it to earth (Top of the suspension strut) the cooling fan comes on so it must be something to do with the system that keeps the fan on when the engine is very hot, even if the engine is turned off. I have been looking for a coolant temperature switch / sender on the engine close to the drivers side. Anyone got any clues please. This is the last job to sort before I get it MOT'd. Wasting loads of time! :brickwall:

[CorradoVR6-Turbo 0]

Welcome to the CF.

 

there should be a tempreture sensor close to the cam cover/inlet side.this sensor is for under bonnet tempreture.