It is never ever too late to start over.
One of the huge handicaps in training a Yorkie is also their greatest asset. They were bred to work independently -- without human intervention. In other words, they don't NEED us to tell them what to do and when to do it.
What has helped me is designating a special "potty place" in the yard. I walk the kids to the potty place and when they potty, then they are rewarded by getting to play in the "play area". If they don't potty outside, I bring them back in and then try again in a few. GOOD LUCK! And when you find a technique that workd for you, please share it with the rest of us.
