Just a quick update on this.
Had to grind the old fan sensor off today because it wouldn't loosen no matter what I tried and now part of the nut is still stuck into the thread of the radiator. Going to take the radiator to a local engineering place along with a new fan sensor that I've ordered and get them to re-thread it. Only problem is that the new fan sensor unit won't be here till next week
Getting there slowly but surely!