A plastic connector having a terminal position assurance (TPA) component receives a radio frequency terminal having a cylindrical casting as a portion thereof in snap lock relationship within the interior of the connector body. The TPA may be resiliently snapped between the outermost "preset" and innermost "set" positions, the former permitting operation of the snap lock lance which comes into play when the terminal is inserted into the connector body. In the latter position, the TPA blocks movement of the lance and provides a semi-circular stabilizing cradle in conforming contact with the terminal body to protect it against rocking motion while at the same time allowing rotation of the terminal about its own axis or symmetry. The TPA may also be moved from the "preset" position to a "service" position which allows access to the connector lance.