Animerica Vol. 8, Issue 7 seems to think the show was not well liked:
I've not seen any schedules other than the WGPR 62 one for January 1st-5th 1990 where the 5 episodes aired at 3pm, which as MasenkoHA pointed out before doomed the episodes because they only aired in two states when the target audience was in school. As we can see here:"It seems that Harmony Gold owned the distribution rights rights to Dragon Ball and Dr. Slump for a number of years in the 1980's, and although no official source will say so, at least five episodes were dubbed by Harmony Gold as pilots for the series. The first and third movies were also dubbed and edited together to form a single, longer film which aired on serveral small stations around the country. The pilot episodes were apparently test-marketed on various independent networks. The response was so lackluster, however, that nothing more ever came of it, and Harmony Gold seems to have forgotten it ever happened. What was it like? Most of the names were changed: Goku was named Zero, Bulma was Lena, Oolong was Mao-Mao, Yamcha was Zedaki, etc. An opening theme that followed the original tune was produced.... Despite heavy editing, it was still an amusing, action-packed show."
However looking at a usenet discussion from the time it sounds like the episodes were repeated in February but there was still only 5 episodes.
Did the episodes ever air at a better timeslot after the WGPR run though? It seems bizarre if Harmony Gold were indeed testing the market Response they could have gotten it a better timeslot. Hell, the movie was shown at 8pm:
Is the idea the response was lackluster a narrative Harmony Gold sprung because they realized after the fact there was no way they could edit the show to their liking? Or do we have evidence Dragon Ball fared poorly compared to other shows in similar timeslots on small stations the vast majority of America didn't have.