A thruster power control box assembly includes a housing having a cover. Inside the housing is a switch circuit and a switch control circuit. The switch circuit directs current from an external battery to a pair of thruster cables that are connected to a thruster. The switch control circuit controls the switch circuit by configuring the direction in which current from the battery flows to the thruster cables so that the thruster can operate in both directions. The housing incudes bushings through which the various cables and conductors pass, and are sealed by a compliant plug and a compression nut on each bushing. A terminal box can be used to connect the various cables of the thruster to their corresponding cables of the thruster power control box.