The unused one(s) may go to the fog lights if you don't have them..
There is also another option switch that goes into that area the Automatic Transfer Case, that you may not have...

 

I didn't think it was used. But, wanted to make sure it didn't come loose. I guess the next thing to do is see if those nicked wires are the culprit. I will update the post when I find something useful.

 

Does anyone know what voltages I can expect at the various wires? This truck is the base model so no DIC, 4WD or Fog lamps.

Also, I did some testing at night.

If I switch from Auto back to off then turn on the headlights, just the headlights turn on. No parking lights.