2000 Discovery Problem - Electric Fan

I have an issue with my 2000 Discovery. Last night when i got home, the electric fan in front of the radiator did not turn off when the engine was shut down. It stayed on for over 30 minutes before I finally broke the circuit at the battery to shut it down. Any idea what might be the issue here?

On another issue, about 5 months ago my ABS, TC and Hill Descent lights came on permanently. I have been told this is most likely the ABS modulator. I have also read though that this is a difficult problem to fix and replacing the modulator does not always resolve this issue. Will replacing the modulator clear this fault? Also, what exactly is not working on the vehicle right now? The ABS still works - I haven't tried the hill descent but I suspect the traction control is disabled at this point. How can I verify this?

Thanks for your help!

The electric fan in the front is for the Air Con, I would suspect either a duff temp sender or stuck relay, though don't quote me on it as I don't have a wiring diagram to hand. As for the three lights there are a few things you can check, firstly the wheel bearings, any play will introduce a bigger air gap to the sensors. If you have an ocilloscope then you can check the output of the sensors, likewise with a good multimeter you can check for open / short circuit sensors.

Have the three light problem myself, yet no fault codes are presant, however while it was last on the code reader we took it for a drive and it showed the front right sensor had an intermittent output, OK I thought change the bearing and sensor, problem is the bearing is only available as a front hub assy complete with abs sensor and for the sum of a little over £200, decided to change it, expecting it to sort the problem however the problem is still there. Now am looking into finding a local ABS specialist, as the normal route at the dealers seems to be to replace parts untill eventually the dead part is replaced, while this in it's self isn't a problem, I do have some concerns about paying dealers labour rates for this kind of approach.

Keep us informed as to what you find, and I will do likewise.