what shows (both sitcos and dramas) did the networks rerun late at night?
in the 70s, ABC used to rerun "BARRETA" (I remember they used to show it Friday nights at 11:30 and our local ABC affiliate would pre-empt the ABC programing and show a movie, then show ABCs programing after the movie, at aproximatelly 1:30-2:00 and I remember it was strange seeing network programing at that hour in those pre-cable days). And also in the 70s they used to rerun "SWAT" and "STARSKY & HUTCH" as well as "FANTASY ISLAND".
In the early 80s they also showed reruns of "THE LOVE BOAT", "BARNEY MILLER" and "CHARLIES ANGELS" and "SOAP".
In the late 70s CBS used to show reruns of "MASH" & "KOJACK".
In the early 80s CBS used to show reruns of "WKRP IN CINCINATTI" and "ARCHIE BUNKER PLACE" also "LOU GRANT".

ABC also used to air reruns of Mannix in late nights. Coincidentally, Mannix was supposed to make new episodes for ABC but CBS refused to renig its contract w/ Mannix so Mannix ceased production in 1975 but saw reruns on ABC sometime the mid-late '70s.

CBS aired reruns of Hawaii Five-O in the mid-80s, namely the dreadful 12th season under the title MacGarrett.