I have an 09 Double Cab with Tow Package and bought an Activator III brake controller. I also bought a Tekonsha Toyota Brake Control Harness (model 3040-P). The harness has 2 connectors: one that fits the connector under the dash and one that fits the Activator III. In the harness it also has a white wire with a spade on it that doesn't seem to go anywhere. Could this be another ground? I used an Ohm meter and found it has continuity to ground. What should I do with this and where should I connect it?