Why does the AC compressor need to match the engine?

[sebmaster]

Hi,

Took my 96' A4 in to have the AC looked at, the guys said that it couldnt even be charged long enough to run a leak test. There is a little corrosion on the pipes nearby but they think its the compressor, and gave me a ballpark figure of around £800-900 to replace it.

I had a look around and it seems replacement compressors vary anywhere from £150 up to £600.

Why does a compressor for a 1.8T A6 cost £120, an A80 £280 and my A4 £500?

Surely they dont change the entire air con system with each engine so why the pump?

[jsmithee]

found this place while looking for a condenser fan, dont know if its useful. a4 1.8t compressor £275 new.

http://shop.coolcaraircon.co.uk/a4-18-20v-turbo-petrol-manualautomatic-aug-97-to-nov-00-144-c.asp

[sebmaster]

Hi, thanks for the link jsmithee. I took my car in and they said it wouldnt be much to fit a new compressor if I found one.

Does anyone know if theres somewhere I can search for the part number of a specific part?