I just got a 2006 limited, v8, "class II" towing package.(I assume it isn't the complete "class III" package, since it does have the class 2 hitch and 4 pin flat wiring) I want to tow my travel trailer, so I need to upgrade. I know I need to install a class 3 hitch below the stock one, and I have a brake controller (not installed yet) and found the plug under the dash. The problem is out back. How do I get the 4 pin converted to 7 pin round? Obviously, the brake lights are there, but I need the wires for the 12V trailer battery and brake output from the controller. Under the hood, the relay and fuse are installed for the trailer brakes, but I just can't seem to find the wires out back. Where are they? Anyone successfully pull this off? Thanks for your help.