bluebob21

I wish to replace an afterrmarket radio with an original radio/cd/cassette player. Unfortunately the original connector running from the speaker/amp has been removed. The plug going into the back of the unit is a 5+7. Can anyone help please with which wire goes to which pin.
I have absolutely no idea where the speaker wires together with the switched or constant +ve connect to, together with the ground wire and all speakers. Any help, much appreciated.