A year ago, my son move in with me to attend college. After his first year, decided he wanted to go to a different college. Prior to attending college, his mother petition court to terminate child support of which was granted. Now that our son has switch colleges, she has requested a modification to have child support reinstated. The college of choice is about a 100 miles from her residence. During breaks he is spending 75% of his time with me. During his time with me, she did not offer a dime towards college and or any expenses nor did I request the courts to make her pay child support. During the 18 years of paying support, every time it came to pay for school clothes, sporting goods, trips, etc, I paid for those items cause she was always was out of money. My question is, since the child is over 18, can he petition the courts to have both her and I pay support so that the money is going directly to him?

He has no say in this. Support is paid to the custodial parent for the expenses of raising the child. If she takes you to court, you provide proof of the amount of time he stays with you to help the court calculate what support, if any, should be awarded.

No. Your son cannot petition for child support; only the parent can.

And, in any case, it is extremely unlikely that child support can be awarded after the child has turned 18.

And, in any case, it is extremely unlikely that child support can be awarded after the child has turned 18.
I know at least in my state they say until 18, UNLESS going to college.

I know at least in my state they say until 18, UNLESS going to college.

The distinction is that, while CS, if in college may be initially awarded, its unlikely that the CS order can be modified later to add such a provision, especially after the child turns 18.