There is no "Eddie and the Cruisers III." The original "Eddie and the Cruisers" was released in 1983, while the sequel, "Eddie and the Cruisers II: Eddie Lives!," was released in 1989.
Both "Eddie and the Cruisers" and the sequel starred Michael Pare as musician Eddie Wilson, a fictional rock idol in 1960s. In the first movie, Wilson has been out of the music industry for nearly 20 years until a reporter begins researching him and his former bandmates, ultimately discovering the last unreleased recording of their music. In the sequel, Wilson is found living under a fake name. After much coaxing, he once again becomes the popular frontman of the Cruisers.