ok, i tied the black/grey wire into the wire going from the brake light switch to the rear lights.
at the rear of the truck, i tied the single brake light wire to two other wires, and tied those two into the mix with the turn signal wires in each light casing.
i still can't get the brake lights to light up when i activate the brake light switch, and now i can't get the turn signals to act individually because they're basically jumpered by the brake light wires. same as before
