AC not working

Hi All, I have problem with my AC. Blue button is ON, blower is working but compressor doesn't engage.I checked all the components from compressor to fuse box and everything works fine when hot wired at the fuse box. Something is missing under the dashboard, any relays there?I know Bentley's doesn't list any relays(except lo fan) but on line catalogs of at least few retailers show black, six prong AC relay for E30's. If that relay exists, where is it located?. At this point i don't know what else to check.Also, system is fully charged and worked perfectly ok just a couple of days ago.
Any help will be appreciated.
Thank You
86 325e