Thanks to D.Wysong & Giles for some comments on the installation of the spade connectors in the plug. There were two issues. 1, the connectors were inserted with the crimp on the wrong side. 2, the little tab on the back of the connector that holds the connector in the plug were not protruding far enough to catch. By carefully opening the tab and inserting them 180 degrees around, they clicked right into place and held when the plug was attached to the voltage regulator.