The series takes place 15 years after the events of Starman (1984).
The trouble is the math does not work. NASA launched the Voyager probes in 1977. This was found by the Starman in the first movie and was his "invitation" to visit Earth. The show takes place in 1986 and Scott is now 14 year old. Which means Starman visited Earth 14 years earlier, which would be 1972 -- five years before the Voyagers were launched.