I've had my 2012 since February of last year. Worked fine all spring and summer, then the cold came back around...
First my lowbeam headlight on the passenger side burned out. Replaced the bulb and nothing happened, so I tried checking my fuse box and replacing the relevant fuses.
That did nothing either, so I got handy and spliced on a new pigtail with heatshrink butt end connectors and the whole nine... It worked for about 3 days then burned out again.
Around this same time my heat and AC stopped working entirely, and I'm 99% sure I fixed it by replacing the blower motor resistor module.
​​​​​​About a month later, the driver side lowbeam just entirely stopped working after a particularly wet snowfall.
Im now down to only my high beams, which do in fact work for whatever reason.
Somebody who knows more about cars once told me they think I have a bad ground wire, and after some googling I found this problem is about as common as the blower motor resistor module problem in 2012 Chevrolet and GMC trucks....

Can anyone tell me if they think this guy was correct? Can anyone provide me resources on fixing this myself, and how much the parts would probably cost? Thanks


EDIT--
The radio/sound system also makes lots of strange screechy noises if I plug anything into the AUX, and it will repeatedly and constantly switch to radio from AUX and vice versa when I got bumps of almost any size.... Anyone know what's up with that?

 

Do you have steering wheel controls? And if so do they still work or no I'm having similar issues with my 2012 as well

 

Did you ever get this resolved? I have to replace my low beam headlights on my 2011 GMC Sierra about every 10 months. I always use gloves and install the factory recommended bulbs. One bulb will go and then within a couple of days the other will go.

Also, curiously, I have the exact same problem with the radio. I did look this up a while ago and apparently it is a common issue with this make and model. Something to do with a short. I’ve been able to stop it from jumping back and forth from radio to aux by keeping an aux cable plugged into the aux port. The cable isn’t attached to anything, just seems to stop the short from happening.

KootenayHerb

 

Here's something to try - disconnect the battery, then clean the ground wire and reconnect it. If that doesn't work, you might need to replace the ground wire or bulb. I found this resource (https://lightninglab.org/chevrolet/silverado-1500/), here you can check your bulb size if you need it.