He played for one season at Cambridge, playing 19 times before leaving the country to play in the American Soccer League once again with New England. After returning to England he joined up with Swindon Town for a brief spell before returning to Cambridge. Turner ended a 15-year playing career with a spell at Southend United before retiring in 1984.
In December 1985, Cambridge United had sacked their manager Ken Shellito and were looking for a new appointment. Turner was appointed as his replacement. He managed Cambridge until January 1990, stabilising a club that was at rock bottom and turning them slowly into promotion candidates. He built much of the squad that he would later hand over to John Beck to take the team up from the Fourth Division to Second Division.
He took on his next managerial position at his first club, Peterborough United, in January 1991 and managed the club until December 1992, going on to be one of the most successful managers in the club's history. He retired from football in 1992 and went on to own the club as chairman before selling his interest to Barry Fry in 1996.
In 2006, Turner teamed up with ex-Peterborough player Lee Power, who was then chairman of Cambridge United, to help out in a temporary coaching role at the club. But soon afterwards he became ill with what was later diagnosed as frontal lobe dementia, and by April 2014 he was living in a nursing home. In the last five years of his life, Turner was reportedly unable to walk, talk or eat solid foods. He died on 27 April 2015, aged 64 years old.