Keeping clean

Hi, sorry seem to be posting lots, am just trying to get as much help as I can.

My son is 15 but will not shower or wash his hair. He's not yet diagnosed, but we strongly suspct aspergers. It explains the keeeping clean aspect as he is just not aware that he needs to!

I've realised that he finds the shower difficult, I think the noises and sensation are painful, so he generally has more success if he has a bath. I have to wash his hair for him as a compromise on the days when he won't have a bath.

Usually he will do his hair because of peer pressure, or if he is doing something social and I can gently suggest that it would be good to do it.  

He hasn't had a bath since a week last Wednesday (!), fortunately he doesn't suffer from BO but yesterday he did smell of wee so I said he needed a bath this morning. He looked so upset when I told him. How do I tell him, encourage him to bathe without him being sad and cross?

Everynight I have to tell him to do his teeth and have a wash.

Every moring I have to brush his hair - if he'll let me (and thank goodness for dry shampoo!), otherwise he goes to school like a scarecrow.

Any ideas please? 

Thank you! :)