Originally Posted by
Spiritual Seeker 
Your riding him and you taking respons. for finding out what is due and reminding him over and over hasn't worked and it sets up a very dependent dynamic that builds great resentments on both sides.
This is exactly what my 15 yr olds mother does. And beyond that she would send emails to the teachers apologizing for his poor performance and promise improvements. We would go into meetings with the teachers and she would walk out with an action item list of "catch up assignments". For the last two years this approach has not worked at all. Loosing "currency" is the only thing that has worked, and even that's with marginal success.
I doubt one can micro manage/project manage an unmotivated 15 year old all the way through high school, college and adulthood. The sooner you let them suffer the natural consequences the sooner they will grow up. It's not easy, but it's necessary.