If she refuses to give you her home address, you're going to have to track her down and/or file a motion for enforcement. You can file a motion for enforcement of a prior order and the court will either hold her in contempt or fine her based on the failure to give her address and the failure to turn over your son for visitation.
These have very, very specific pleading requirements and since attorney's fees are awarded, I'd strongly recommend consulting a local attorney in the matter. Even if you don't know her home address, you can still have her served at work.
I agree with Mr. Cohan, most Decrees will include language requiring the parties to notify each other of a change in address along with notifying the Court and Attorney General of the change. There are likely several violations of the Court Order that she can be found in Contempt for. Hire a competent attorney to file a Motion for Enforcement on your behalf.