^^ good suggestions! And try to remember to reinforce the words....
OUTSIDE!
PEE PEE (or whatever you say)!
NO!
when you go outside, for any reason, say OUTSIDE like it is the most amazing place on earth...and reward your dog with a pat just for going out there. Then reward them and praise him (BTW, a reward can be affection, doesnt have to be food) for peeing out there.
Then when he pees in the house, a sharp NO followed by OUTSIDE/beeing carried on trip outside/and then--and this is key: Lots of praise for going outside.
Be sure to watch inside for signs when he is getting ready to pee, say pee pee outside in an informative tone, and then scoop him up and take him out....and each time you get him to pee outside, HE IS THE GREATEST DOG IN THE WORLD....
First thing in the morning, you say pee pee outside in an informative tone, carry him out, and fuss like mad when he pees.....Say PEE PEE OUTSIDE in an happy praising tone....
Eventually he will get the meaning...pee outside good. pee inside bad.
My little doxie takes herself outside (cat door) in the morning to pee, and when i spy on her, I can see that after she does it, she wags her tail like she is so happy with herself.....and weiners are hard to train, too.
This all works for poo, too.
Do use the enzyme sprays to help clean up any accidents inside, these scents make it harder to train to pee elsewhere....
Also, if you mess up and miss the opportunity, and he has an accident, just say NO PEE PEE OUTSIDE and take him out and praise him....You have to anticipate it for a while, and not punish him too severely, otherwise it is confusing and anxiety causing, KWIM...
Good luck...this will pass, he will learn eventually.