Prehaps, college is not appropriate for your son. Have you considered vocational job training instead? Does he like working with his hands rather than reading and studying all the intellectual, often abstract "stuff" that colleges and universities require?
Oftentimes, it can be easier to find a job when a person has the skills of an auto mechanic, carpentry, masonry, landscape design and grounds keeper, welding, airplane mechanic, plumbing, Electrician and many other types of Trades...while thousands of people with college and other advanced degrees remain unemployed. This is quite evident by our current economy.
Or prehaps your son just needs to take one year, or two, off from any college studies and work in a minimum paying job for a while. After being in school since the age of kindergarten, maybe he just needs a "break" and to experience the real world. Then, he will soon realize how important an education is to a better lifestyle and he will be more willing to work hard at doing his best to succeed in college.