Abstract: A connector-terminal assembly for passing electrical current through a furnace firewall. A one piece insulator fits through a hole in the firewall and is braced to the firewall by a single retainer clip. A connector suitable for high temperature use is slideably mounted in a hole centrally through the insulator and retained therein by the electrical terminals on either end thereof. The insulator is mounted in the firewall independently of the connector mounting in the insulator, and vice versa. The insulator is mounted to the firewall free of compressive stress along the connector axis and the connector is mounted in the insulator free of tensile stress along its axis to allow for heat expansion of both components.