I am still trying to potty train mine the same way. I'll give you my experiances you might can try. First are you leaving him behind a gate so he cannot roam (since he is not potty trained) If possible make his gated area more confined. Push it back till he gets used to using it. If you catch him using it any where else pck him up right then and say pee-pee or what-ever you call it and place him on pad. The more he starts using it you can give him more roaming room. Mine was almost 99.9% potty trained till I brought home the female. And it all went down hill. He is back behind the gate cause he now for sure wants to mark his spot. Peeing everywhere but on potty pad. Read somewhere last week about putting one of the small orange cones in middle of pad (he is now hiking his leg) to get him to pee there and believe it or not he is using potty pad and aiming for the cone. LOL.
The more he uses the potty pad then you can start moving it closer to door if possible. I am no expert but this is what has been working for me. Trust me it has been a major trial and error. I keep saying I am going to win. One thing I have found if the pad gets too wet he want go on so you may want to not spray it with the scent stuff. I have never used that so I know nothing about it. Also when the female uses the pad he for sure wants to pee on that. LOL
