On my 2008 Mk3 CRV the air con relay is in the fuse box at the rear of Engine compartment, triangle shaped box near to the Battery on the Passenger Side , when you remove the fuse box cover look at the instruction for the number of the a.c. relay , mine is R6 in the box, If in doubt check the owners Manual or if you don't have one , go on Google and look for Fuse Check.com put in your vehicle details and you can get all info on all the Fuses and Relays for your Car, print this off for future reference
Hope this helps Alan