Recently I failed to remove the shore power cord from my sailboat, 1981 Catalina 27, as l left the dock and the cord pulled the female receptacle from the boat. The receptacle is marinco 30A, 125 volt unit. I can reuse it but I understand the the three wires now exposed on the boat are color coded and must be connected to the correct prong on the receptacle. The new receptacles have the color code on them but this older unit has nothing. Any advice on which wire goes to which prong would be much appreciated. Thanks