As you can see, there apparently was some heat back up under the bumper on the drivers side. You can see that all four wires at some point fused together. I pulled them apart slightly to get the picture of the bare wires. Also, harness box itself got hot on the opposite said as you can see a hole melted through. The good news is it is so easy to replace a young child could do it. The new harness is under $40 and comes already wired with plug n go connectors. Just unplug both connectors at each tail light. Plug in the new harness at each tail light. Run the wires out of the way. Mount the trailer plug where the old one was and you're done.

Here's where I found mine.
http://www.etrailer.com/Custom-Fit-V...id=19991171397

 

Looks like something went wrong inside that box.

 

That e-trailer kit is the same one I have installed on mine (aftermarket self install)

Be sure to keep the prongs "water free" when not in use or it could short out your system, and you will lose dash/driving lights and brake lights.

There is a fuse in the Driver Side of the Dash, and also one under the hood that were blown out on mine (thanks to the excessive salting of Detroit roads and an open plug thanks to tire company that replaced my spare tire wheel winch. ).

 

I had a problem like that when everything froze here. Then, when the ice melted, there was water in places that usually it wouldn't get to and it shorted out several of my connections.