Splitter Harness for Vehicles with a Proprietary Interface Port Connector

A splitter harness and a method of installing the splitter harness are provided. The splitter harness includes a main harness segment having a first multi-wire harness connector and a second multi-wire harness connector at both ends thereof, an On-Board Diagnostic (OBD) port harness segment having an OBD port connector at an end thereof, a signal splitter, and a power signal provider for providing power to the OBD port connector. The method includes unplugging the vehicle connector cable connectors, connecting the harness connectors, and connecting the power signal provider to a power source.