6 Month old puppy-housetraining question

Hi,
My 6 month old puppy does not show any signs when he needs to eliminate, and will just go in the house. We take him out regularly but he hates the wet grass and if it's late at night or first thing in the morning I have to force him to go out to the bathroom. He is even reluctant to get out of his crate first thing in the morning because he knows he will have to go out onto the dewey grass. Therefore he is still having a couple of accidents per week.

Is it unusual they he doesn't show any signs of needing to eliminate? Should I start training him to ring a doggy bell? I am afraid he will not ring it because it means out on the wet cold grass ;)

When it rains, it is a non stop battle of trying to get him to go to the bathroom, and sometimes he doesnt go, only to eliminate in the house when he gets inside, argh!

Any advice would be appreciated!