The white wire on the vehicle's 4-way flat connector will not support the ground (-) functions on the combination harnesses 4-way flat and 7-way connector. Using 12 Ga. (minimum) wire and butt-connectors, connect the remaining wires to the appropriate functions as listed below.. The Curt Echo Brake Controller part # C51180 is a great choice because of its convenient and simple installation. The 7-way connector that you mention part # A10-7084VP pugs into the 4-way connector you purchased part # C56217. The white wire from the 7-way plug needs to be grounded to a clean bare metal surface on the vehicle's frame.
The Curt 7 Way Plug Diagram is designed to provide power to the brake lights, running lights, left turn signals, right turn signals, and reverse light. The diagram also includes a ground wire, which is necessary to provide a complete electrical circuit.. See the CURT catalog for application information. Page 10 WIRING DIAGRAM IMPORTANT: Make sure that both positive and ground connections are made directly to the tow vehicle's battery.