Question about a loose wire on a '14 Silverado

[Mattbull88]

Hey everyone, got a question someone might be able to answer. 

 

I've got a '14 Silverado 1500 WT.  At the back under the bed on the driver side near the spare tire is a wire hanging down with no end. Originally thought it was a frame ground because the outer casing is black but today I took a pair of wire stripers and found that there are 3 thin wires inside of the black sheathing. They are Solid Red, Solid Yellow, and Solid Black. All lights on the truck work, the trailer lights all work when plugged in too. 

 

Anyone have any idea what this could go to? I currently have it rolled up and ziptied to the frame.  Thanks for any help.

[tbarn]

Pictures