^ HE wanted Han to be killed off in ROTJ. As regards the phoning it in, it probably doesn't help that he was given less to do with in this movie; although we saw Han finally become and out and out willing rebel, he was still much less interesting than he'd been as a an anti-hero.
And to be fair to Ford, the best parts of Jedi were the scenes between Luke, Palpatine and Vader anyway.