CRDA, which is managing the $14 million renovation of the once-dilapidated Dillon Stadium near the Colt manufacturing complex, had hoped to use the existing stadium lighting system, but it couldn’t be upgraded to the standards required by modern television broadcasting. Installation of the new lights required structural changes below ground to work around storm drains and sewer pipes, particularly on the western side of the 6,000-seat sports venue. Four new, 120-foot lighting poles were all in place last week.