My older brother dropped his AP courses in high school and took as much auto shop as he could fit in, despite "counseling" from the administration. He worked as an auto technician for 12 years, picking up an AA in Toyota along the way, and was the head diagnostic tech for his shop the last few years.
But where to go from there? He didn't want to open his own shop, and he didn't want to contemplate doing the same thing for another 30 years.
So he went back to school and now he's a licensed practical nurse, with lots of career progression options available, and he's much happier at work doing something that is challenging and working with people.
I would happily have hired him--who knows next to nothing about computers--as a desktop tech over most of my coworkers at any of my jobs. You can teach computers, but some people cannot seem to grasp cause and effect and customer service. I could have made him a fantastic computer tech in a few months.
On the other hand, I threw away a viable (if unexciting) career in IT to become a soldier, so maybe I'm the wrong guy to offer perspective.