How does it "look like it is connected"?

For my 10.10 installation, I had to manually load the correct
"specialty" driver. Then set up the wireless, also by hand. I have
seen that 10.10 does not start-up and connect to wireless automatically
every time - does not work sometimes on return from hibernation. You
might try starting it manually - there should be a hard-to-see icon on
your task panel - it will "spin" if the driver is searching. You can
also click on the icon and go to the appropriate selection (mine is
"connect to hidden wireless network"). You can also create a new
wireless network.