CGimpala05

I recently replaced my original radio/cassette with a factory radio i bought at a junkyard....this one is a radio/cassette/cd....the radio and cassette work fine, however, the cd player will not recognize that a cd is being put in...even with the cd pushed all the way in, it fails to switch over but the eject button works fine....I was wondering if the cd player has gone bad or if i am missing wiring since the original did not have a cd player....thx for any help

shawnvw

probably a bad radio...wiring is identical between the 2 radios