If you have a Delphi aircon compressor with the 'loose centre bolt' where it won't engage, then here is how I managed to fix mine as a DIY for about £40.
If your AC system looks fine - topped up, no leaks, all seems ok via VCDS logs, then this is worth looking into.
I did this on my Tiguan last week, but it uses the same compressor as the mk5 and loads of other similar era VAGs so this might be helpful for someone.
What happened was the splines on the shearplate became rounded off, so it stopped engaging with the compressor shaft. The compressor itself was fine.
From underneath the car, remove four T27 torx screws from the shear plate (no need to slacken the aux. belt, remove tension or anything like that, it is all done in situ in 10 minutes), then pry the old plate off.
Once off you will see if the centre has rounded. If the stub has sheared off then your compressor will have seized.
It is worth doing this just to check before purchasing anyway.
I put the replacement plate on and immediately I had cold air.
I can only imagine how many compressors and other bits have been swapped out over this.
Here is a pic of the old plate
And here is a side by side with the new one
I got the new plate from ebay.de as it is an aftermarket part.
