Engine Noise caused battery drained S320

[stupiddoc]

Hi expert champs need pearls of wisdom

Got S320 (year 2000) turned off engine and heard noise like vaccum from engine - kept on coming even after 20 min
started engine for 2 min and turned off brought down the noise but very minute amount of humming still coming

1- radiator fan was not moving
2- Air con recently refilled and used everyday
3- Temp gage within normal limits

When I opened bonet - felt the black plastic hood quite warm and slight burning smell

Anyway went to bed and in Morning found battery flat ( Bosch batter replaced 3 months ago)

All this is new onset
Any suggestions please

 

[miro]

Might be related to the viscous coupling at the fan or engine control unit.

 

[stupiddoc]

Well its seemslike after dead battery my soft closing and air suction for locks doors and boot not working. No hissing sounds anywhere

Any ideas what I do to rectify this please

Thanks