cooling fans

93 euro 3.1L my car overheated the other day i opened the hood and the radiator was shot and one cooling fan was deff on i changed it out the next day with one from the junk yard i know but it was all i can get without having to wait days to get it but now the fans don't turn on at all i changed the temp sensor but no luck right now i have the temp sensor unplugged so it wont overheat but it keeps both fans on all of the time and it also trips the cel light any clues why it would work before i changed the radiator but not after