If I am living abroad and a Thai court has ruled that I should pay for child support, will this be enforced?

Yes, this will be enforced. If you have any property in Thailand, the court will place an order to seize your property to be sold via auction; then the proceeds from the auction will be used for the child support. If you do not have any property in Thailand, the Thai court will work cooperatively with the court in the country where your property is located to seize your property and sell them in order to pay for child support.