Opening the lines of communication....

Communication has always been important to me because my parents relationship was torn apart by lack of communication. My relationship has always struggled in the communication department. I just don't know how to correct it because it just seems like no matter what I try, my fiancé just won't open up to me. Anytime I try and talk to him about something he just shuts down, it doesn't matter if it's a fight or just a generic conversation about plans for the day. He just shuts down and won't say anything.... Has anyone else gone through this? How did you finally get around it? I don't want to be stuck in a relationship where there's no communication forever but I don't want to give up or lose him either. We've been through a lot together but we have to find a way to get over this road block....