Protective cover devices for associated electrical connectors include a one-piece molded polymeric body including at least one of: (i) at least one stud that is closely slidably received into a corresponding socket of the connector; (ii) a skirt that comprises a recess that receives at least part of the electrical connector therein. The protective cover device is adapted to be engaged with the associated electrical connector to inhibit contact between a surrounding corrosive atmosphere and at least one electrical contact of the associated electrical connector.