How about fabricating a short sleeve with a threaded bung for the sensor to go in between the bottom radiator hose and the radiator? That would keep your wiring short and easy to hide as well as allowing your fans to turn on/off relative to the temp of the water exiting the radiator.
This sounds like the best Idea to me as it would give the most accurate reading of the radiator temperature. But you have fixed your problem so that's only my 2 cents of post-thought.
