Merc w210, petrol, auto, E240, 2600cc, year 2000

[Gogoogs]

Help, my air con didn't blow out cold air even though the air con clutch engaged. 2days on my engine fan was on full even though the engine was switched off. The fan drained the battery. I then recharged the battery and on re-conecting the battery noticed the fan went on full speed again but then after 2mins stopped. I proceeded to drive the car and the engine fan visit workshop message popped up on the dash as soon as I switched on the climate control. I subsequently had the air con charged fully by a professional. The air con now works for a bit and then the engine fan message pops up and the cars engine starts reaching a temperature of between 80-100 degrees according to the temperature gauge and no cool air blows into the cabin as the Aircon clutch disengages. On advise I've changed the air con pressure switch with a new genuine OEM part (professionaly recharged the Aircon again) plus I've replaced the engine fan with an after market fan. However to no avail. All fuses have been checked and all wiring looks good. I've been thiking of replacing the water temperature sensor but think it may be time to get it diagnosed by an independent. However any thoughts would be gratefully received?