TDV6 Engine fan fault

[Disco 3]

Hi there, recently I purchased my first Landrover, Discovery 3 2006 TDV6 with 220k. Not long after picking the car up I realised the aircon was switching itself off in traffic whenever the car was stationary. So I had a radiator/ aircon workshop look at it. He put the car on his testing equipment and when the aircon did its switch off, the aircon pressure spiked off the chart. At first he couldn't find out why, but then he realised the engine fan wasn't hardly moving which was causing the car to overheat a little and the aircon to switch off. So he diagnosed that as the problem. So the next week I had the engine clutch fan replaced at the cost of $870.
Initially this fixed the problem but then the other day while sitting in traffic, the aircon switches itself off again, some two weeks after the new fan.
When I got it home I watched the fan while on idle and it was barely moving.

I'm hoping someone has had this issue before and knows the fix?? My hopeful guess is a engine coolant sensor or something cheap as the new electronic engine fan seems to have been a total waste of money.

Thanks in advance.

[theNEWT]

HI. Sorry for your woes. I dont have this model but thought I'd chuck my thoughts in. The AC turning off at idle is consistent with a failing viscous fan and/or failed electric fans, radiator, front end blocked with bugs etc....poor air flow = over heating.

If the new viscous fan is hardly moving at idle its not working. It should run at the same speed as the engine ......if the engine is hot. If you studied it when the engine had cooled it will disengage and appear slow.

Make sure the electric fans are coming on with the AC turned on.