Mystery wires under dash

[Brian Wilson]

2007 yukon denali. I have a couple thick wires under my dash that paper to be factory but taped up. anyone know what they are or have them? was a brake controller optional on these trucks?

 

[Tonyrodz]

Looks like they go above the obd connector, and the other ends are cut. Maybe someone installed an alarm at one time .

 

[Wagnasty]

Trailer brake control box?