An electrical system, comprising: a first electrical connector suitable for being coupled to an electrical panel; a second electrical connector suitable for being coupled to a testing device that is configured to test a component coupled to the electrical panel; and a retaining harness assembly that removably connects to the first and second electrical connectors to maintain a secure mating relationship between the first and second electrical connectors , wherein the retaining harness assembly comprises: a rear wall connected to opposed lateral walls , wherein a connecting chamber is defined between the rear wall and the lateral walls ; a lower ledge separated from an upper ledge by a flange-receiving slot , wherein a flange of the second electrical connector is received and retained within the flange-receiving slot , wherein the lower ledge exerts a first retaining force into the flange ; wherein said retaining harness assembly further comprises a retaining collar that secures around a portion of a backplane of the first electrical connector and abuts into a torque ring of the first electrical connector , said torque ring arranged to provide a secure connection between the first and second electrical connectors when torqued or otherwise rotated, wherein the retaining collar exerts a second retaining force into the torque ring , wherein the retaining collar includes one or more first recessed areas configured to conform to a portion of an outer surface of the backplane , and the opposed lateral walls are configured to be deflected into an open position in order to remove the retaining harness assembly from the first and second electrical connectors . a first electrical connector suitable for being coupled to an electrical panel; a second electrical connector suitable for being coupled to a testing device that is configured to test a component coupled to the electrical panel; and a retaining harness assembly that removably connects to the first and second electrical connectors to maintain a secure mating relationship between the first and second electrical connectors , wherein the retaining harness assembly comprises: a rear wall connected to opposed lateral walls , wherein a connecting chamber is defined between the rear wall and the lateral walls ; a lower ledge separated from an upper ledge by a flange-receiving slot , wherein a flange of the second electrical connector is received and retained within the flange-receiving slot , wherein the lower ledge exerts a first retaining force into the flange ; wherein said retaining harness assembly further comprises a retaining collar that secures around a portion of a backplane of the first electrical connector and abuts into a torque ring of the first electrical connector , said torque ring arranged to provide a secure connection between the first and second electrical connectors when torqued or otherwise rotated, wherein the retaining collar exerts a second retaining force into the torque ring , wherein the retaining collar includes one or more first recessed areas configured to conform to a portion of an outer surface of the backplane , and the opposed lateral walls are configured to be deflected into an open position in order to remove the retaining harness assembly from the first and second electrical connectors . <EOS>