look behind the dash bezel, youll see all kinds of wires that arnt hooked up. Doesnt mean your missing shit, just means your truck didnt come with a certain option and what not.
IE all these trucks (tahoes/yukons/burbans) all have the fog light pigtail behind the dash. Its only used if
1) you buy the oem fog switch and wire something in
2) if your truck came with fogs (denali/escalades and tahoe limiteds)
sooo being said, dont get too far ahead of yourself thinking ***** messed up. lol Its common in all cars. They make 1 harness for that group of cars/trucks and some of those things just arnt hooked up.. no worries maynnee