Noisey auxiliary fan when air-con on

[alex100a]

I recently replace the air conditioning evaporator on my A6, which worked a treat however I have since been having an issue with the auxiliary fan kicking in almost all the time, which I believe should only happen when the car is getting too hot.

If I switch the air con off the fan stops so it’s obviously due to the air con rather that the engine.

Does not cause me any problems as such but keep being told my car sounds like a vacuum cleaner!

Any idea?

Regards
Alex

 

[votblindub]

Bad sensor thinking the car is hotter than it is? Maybe badly calibrated sensor? Maybe the fan itself is loose and just vibrates a LOT?