Cooling fans won´t start

Dear All,
My ´99 1.8 Freelander 1 has a problem (surprise, surprise!) with the fans not kicking in.
The fan works, as it goes on automatically if I disconnect the coolant temp sensor.
I´ve replaced both sensors and electrical contacts. The multi function cooling fan relay has been replaced, the thermostat is opening (tested) but still no joy.
A garage charged me a fee to tell me it was the control unit but they couldn´t specify whether it was the ECU or the multi relay. The relay was changed and the good people of FreelandersSpecialist tell me that the ECU ought to be ok if the fan is kicking in as a safety feature when disconnecting the sensor.
The diagnostics port is defective so that´s no help either!

Would any of you bright sparks have any other suggestions?
All best from Norway
Brendan

What make you think the fans should be running? The 1.8 uses the same cooling system as the V6, but the V6 puts 3 times as much heat into the rad, so the 1.8 is basically over cooled by a massively over sized rad. This means that the cooling fans seldom come on in normal operation, even when it's warm weather.
You've proven the system functionality by getting the fan to run when a fault is detected. I suggest that you measure the actual engine temperature, to see if the engine has reached the 108°C required to put the fan on at low speed.

Thanks Nodge for the response.
I understand they seldom come on. I never hear them in winter. I’m at 63 degrees North!
I wouldn’t have given it any thought but the car is losing coolant externally. Seems to be leaking between the head and the block. Thought it could have been the elbow, so that is also changed with a brand new one.
The temperature is certainly getting high enough. While testing it, after changing parts, I let it idle for too long and the thermostat housing cracked in two right after the temp gauge went skywards!