Plug and Play.No cores or additional wiring required.Constructed using OEM connectors and seals.Made with high temp TXL wire (-40C to +125C operating temperature) with adhesive shrink tubing.Wrapped in lightweight nylon loom with -94C to +257C operating temperature.Includes built in charge harness and improved groundsRetains OEM AC, wipers and oil pressure sensor.Retains OEM alternator dummy light and reverse lights.Retains OEM Speedometer (needsSGI5 Unit) and tachometer (needs calibration).Works with OEM dash instruments gauge cluster.