He opted not to sign a new contract in the summer of 1998 and moved to Sunderland but it all went wrong when he suffered a serious illness that was to affect the rest of his career.
On his Sunderland debut against York City in the League Cup he struggled to the extent that it got him on the wrong end of Peter Reid's tongue, but he had contracted hepatitis and once confirmed Harrison said Reid was a massive help to him.
He made a brief return to Burnley on loan towards the end of the 1999/2000 season, making the subs bench at Cardiff, but he didn't make an appearance.
Harrison dropped into non-league football and from 2005 until this year he was with Hyde United, playing his last game in January at the age of 38.