fabia 2008 air blower consistent working, radio side button working fine showing more or less even off.

but air blower working in full speed.

 

note: heat control and radio working fine, fan speed up and down showing on the screen but does not actually working

Possibly fan speed resistor is borked.

Probably the control module version of the resistor pack failed short circuit.

Current part number for RHD cars is 6Q2907521B. Awkward to access/replace on mk2, I seem to remember.

Had exactly the same issue and have recently fixed this.

 

Fan had 2 speeds - off and full tilt.

 

It is a common fault on all VAG cars of that period.

 

Part is about £35 from Skoda, or I paid £12 for a knock-off from eBay.

 

A bit fiddly, but takes about 30 mins to do.

Disconnect the battery, have a cup of tea and wit around 20 mins for the airbag system to discharge.

Remove the "top" glove box, this allows access into the dash to the passenger airbag, remove the 3 torx screws holding it in.  Don't drop the screws, they'll be lost forever and you'll have to order more from the local dealer!

Using a trim removal tool - not a screwdriver prise the airbag out of the top of the dash and disconnect the wiring and set aside.

Looking through the windscreen you can seen the resistor pack towards the centre of the dash.

reach in and turn to remove from its housing and remove the wiring. (note which way this fits!!)

 

and as the old Haynes manuals used to say - refitting is the reverse of removal.

 

Honestly if I can do it......