Feeling kind of stupid here...
I bought a Prodigy brake controller, as well as the Toyota specific wiring harness to make the install easier. The side of the harness that plugs into the Prodigy has 5 wires: blue, red, black and 2 whites. All the wires, except for 1 white wire, are connected to an adapter that plugs directly into the truck connector tucked up under the dash. However, according to the instructions, "the white wire must be connected to a suitable ground location. The negative terminal of the battery is a suitable ground location in the absence of a trailer tow package connection."
What's throwing me off is 2 things: 1) none of the posts I have read here have mentioned anything about this wire, only that it's a simple "plug and play" install, and 2) if this connector is a Toyota specific connector designed for trucks with a tow package, why is the wording in the instructions contradictory? It first says that the wire must be connected, then seems to indicate that if you have a tow package that it's not necessary.
So what's the correct answer? Does it need to be connected or not? And if so, where did you all connect it?