Ford Freestar Trailer Wiring | etrailer Trailer Wiring Harness Installation - 2004 Ford Freestar. Today on our 2004 Ford Freestar, we'll be installing the Curt T Connector Vehicle Wiring Harness for factory tow package four pole flat trailer connector. It's part number 56073. To begin our install, we'll start underneath the vehicle near the center, just behind the rear bumper. Ford Freestar Hitch Wiring | Harnesses, Adapters, Connectors When you tow with your Ford Freestar, you’ll have no problem making the electrical connection to any trailer with our selection of harnesses, adapters and connectors.