Upon request of the obligor, the court shall immediately authorize service of an earnings withholding order. Notwithstanding any other provision of this Part III, a court may at any time issue an earnings withholding order, in a contempt or other proceeding, if: the recipient or the support enforcement agency has filed a petition that includes a request for an earnings withholding order; and the obligor is in arrears in support payments of more than 30 days. A hearing shall be held if the obligor appears and contests the issuance of the order. The amount of the wage withholding order entered under this subsection: shall be enough to pay the support as originally entered by the court; and may include a part of the arrearage.