I am unable to renew my American passport due to an ongoing child?
Simply put, trying to enter the USA under any passport other than a USA passport will make you subject to all the checks non-USA citizens go through. And you should check whether you will also need a visa. If you do, you could be subjected to immigration laws too. I think it is likely you will be questioned at immigration about the purpose of your visit etc as all aliens are. Lying at this point is a dangerous game to play. Telling them you are actually a USA citizen will likely see you arrested under the child support case! You think you have issues now over what I assume is your failure to pay child support. Try to escape your responsibilities playing fast and loose with another countrys passport could potentially land you in even more trouble than you are already in.