The pulley wheel is making an awful noise when the car is running (probably worn brushes) & i would like to know if it's possible to replace just the pully wheel or do i have to replace the whole AC compressor?

Is the AC working?

When the compressor experiences too much resistance (e.g. trying to compress liquid instead of gas) the pulley shears off its rubber coupling; could this be what has happened?

AC button lights up & it seems to be blowing very cold air but not sure if it's the AC or cold heating settings

Are you sure it's not the alternator or tensioner pulley bearings making the noise?

When i turn the AC wheel by hand the noise is coming from that

I have a similar problem with my Fabia - there's a squeal/screeching noise coming from the alternator area but it's worse when there's load on the engine i.e. all lights on, AC on etc. Diagnosed by VAG specialist as a seized alternator pulley which is getting replaced on Thursday - it should free wheel in both directions but mine would only go one way. I'll let you know how I get on.

 

EDIT - only just read your post above.

Edited 11 April, 201610 yr by Dazza95

Would i be able to just bypass the AC unit (smaller belt) & would it make any difference to the car?

No idea tbh, the alternator pulley solved my problem

I have a similar problem with my Fabia - there's a squeal/screeching noise coming from the alternator area but it's worse when there's load on the engine i.e. all lights on, AC on etc. Diagnosed by VAG specialist as a seized alternator pulley which is getting replaced on Thursday - it should free wheel in both directions but mine would only go one way. I'll let you know how I get on.

 

EDIT - only just read your post above.

You sure you have got that the right way round. It should free wheel in one direction and drive the other. Otherwise its wouldn't spin the alternator. when they fail they lock up and drive in both directions    You can normally spot a failing one by the belt tensioner jumping around a bit and it always wears the belt out faster

Edited 14 April, 201610 yr by SuperbTWM

You sure you have got that the right way round. It should free wheel in one direction and drive the other. Otherwise its wouldn't spin the alternator. when they fail they lock up and drive in both directions    You can normally spot a failing one by the belt tensioner jumping around a bit and it always wears the belt out faster

 

Yep you're right, got that mixed up, doh!