Do you think that the dissenting juror planned along to try to convince the others? What were his methods of persuasion

I think you mean the 3rd Juror. I don't think the 3rd juror planned anything. He just had his own issues about race and relationships cloud his judgment. 3rd Juror is the last to be convinced and only changes his mind once he realizes that he is only projecting his feelings about his own son onto the defendant.