Hey, we got same problem (and same car too) but i don't know if we have the same simple solution. Mine was solved by spraying electrical / electronic grade contact cleaner to the terminal to where the relay of the compresor is inserted. (beside the battery - the smaller black box) My mechanic had tried checking all components of my A/C but all are working fine except that no 12V power is supplied to the compressor. When the cleaning of the terminals was done, its all ok.

Saved some bucks if my a/c is not completly diagnosed! Its been almost a year now and still doin fine.