Lost all my contacts on iMac when I upgraded software All the contacts are on my iPhone but when I go the iMac all it says is no cards.  Preferences has the contacts checked and view groups show all the names but no data for the card?
It sounds like your iCloud is not configured on your Mac. Go into system prefs and make sure you are signed in to your iCloud account, and make sure it's the same iCloud account that your phone is signed in to.