Disclosed is a method and structure for sealing an electrical connector. The structure includes a sealing insert for insertion into the housing of an electrical connector. The sealing insert has a flared lip spaced from and extending above a base and the flared lip has a diameter that is larger than a diameter of the base. The sealing insert further includes a retention feature and at least one electrical pin guide. The sealing insert is inserted into the housing of an electrical connector after applying a form in place sealant inside the housing. The flared lip forms a seal against an inner wall of the housing and the retention feature of the sealing insert engages a retention feature inside the housing thereby locking the sealing insert into the housing and forcing the sealant into a sealant gap formed between the housing and the sealing insert thereby sealing the electrical connector.