I have 2 yorkies that we pad trained. The older one is about 15 months now, it was really hard when we got him around 3.5 months old, but like everyone said, consistency and PATIENCE. He is the best now, he does not go but the pad or when he is outside in the backyard and he sees my older maltese go, he now goes outside too.
Now my new puppy who is 8 months now ( we got him a month ago) was never potty trained. We are having too many challenges with him. He will pee in his crate, drag his poopoo inside and eat it..
But, we are just being consistent and put him in the play pen, and we made his crate for sleeping at might a lot smaller so he can't move too much, so far, he has not had an accident inside his crate at night. When he is in the living room area which is all tiles, he knows to go on the pads, but once he gets on the carpet area, he just goes everywhere.
However, we have seen a huge improvement in just a month.. Be patient, and buy lots of the enzyme cleaner.
. They will get it.....
Good Luck.,