Air con drive belt tensioner
 

A little while ago I had problems with the air con - which did not work at all but also had an irritating whine which rose and fell with engine revs and disapeared the instant the "econ" button was pressed.

The air con was fixed - including a new compressor and is working fine- but the whine is still there. Even with my luck it seems a bit unlikely that the new and old compressor would both produce exactly the same whine - so I am assuming it is something else, and the drive belt tensioner seems the most obvious thing to change next.

Anyone know where I can get a new one from for a 2004 CDTi ?