On April 15th, 2015, Facebook will no longer support AIM Chat integration. For more information please read Facebook ends support for AIM chat integration.
Here's how to set up Facebook Chat:
1. Sign in to AIM.
2. Do you see "Chat with all your friends on AIM" at the top of your Buddy List? If so, great! Click Login with Facebook.
3. If you do not see "Chat with all your friends on AIM" at the top of your Buddy List, click Options.
4. Click Add to Buddy List.
5. Click Set up Facebook Chat.
6. A Facebook sign in window opens. Sign into Facebook, then click Allow to allow the requested AIM permissions.
7. When you're finished, click Done.
That's it! Now, take a look at your Buddy List in AIM. It should have a "Facebook Friends" group. Chat by clicking any name in that group, just as you would with anyone else in AIM.
Note: Facebook chat only works with AIM 7.2 or above (or AIM for Mac 2.1 and above). If you’d like, you can update your current AIM version at www.aim.com.