radiator fan defies all attempts to make it work.

[emtee]

I've changed the thermometer and housing,
Changed water pump, fan switch on rad,
Changed the fan, Changed the rad in case it was blocked or filled with crud.
I've changed the relay to the right of the steering wheel, renewed the fuses above the battery and in the fuse box at the side of steering wheel.
I've tried everything I can humanly think of, can anyone please point me in any direction to make this thing work?
Thank you in advance.

[emtee]

Please? I'm at my wits end whatever that means really?
Anyone, wild guesses appreciated.
Stab in the dark.
Anything?