Ford seemed to regret his last appearance on Jimmy Fallon...
01 Nov 13 - Harrison Ford, Padma Lakshmi, Big Sean feat. Kid Cudi
01 Dec 15 - Harrison Ford, Seth MacFarlane, JoJo
...but not on Kimmel. I don't know if he appeared much or at all last decade when the show aired after midnight. From Epguides:
26 Jan 10 - Harrison Ford, Kristen Bell, Silversun Pickups
11 Nov 10 - Harrison Ford, Gary Dell'Abate, Edward Sharpe and the Magnetic Zeros
28 Jul 11 - Harrison Ford, Lady Gaga
17 Apr 13 - Harrison Ford, Anthony Mackie, M83
08 Aug 13 - Harrison Ford, Keri Russell, Joan Jett
29 Oct 15 - Harrison Ford, Katie Lowes
21 Mar 16 - Harrison Ford, Elizabeth Olsen, Cam