The "special rules for children of divorced or separated parents" in publication 501 no longer apply to you, there is no state where a 19 year old is still a "minor".
The normal rules still apply. A child who is 19 can be a dependent of the parent they live with more than half the year, if they are a full time student and did not provide more than half their own support. If the child is not a full time student, then the child can't be claimed as a dependent by either parent if the child's income is more than $4300.
When your child turned 18 (or 19 in some states) the court order allowing you to claim him as a dependent even if he does not live with you, lost its legal force and effect.
