I've got a '12 1500 5.7 4x4 with a 90+k on it. I've only owned it a year and noticed a whine (not a chirp) from the belt. It's constant but it gets worse when it's raining and actually doesn't make any noise until its been running about 30 seconds.

I started out with the cheapest parts and replaced the idler and tensioner pulleys (not the tensioner just the pulley, that's next) as well as a new belt. It did disappear for a day or two. I couldn't see anything or hear anything obvious with the stethoscope so while I had it in the shop for an inspection I asked them to take a look at the belt. My mechanic said he didn't hear anything. Short story long but I lifted the hood and just stared at the mechanic waiting for him to say "OHHHH you mean that noise". Nope. Instead he explains to me that he's deaf in one ear. LMAO. He's a good guy and they do good work. Well most of the time.

Short story long I still haven't found the problem. Reason for my post is two fold. First I found a pretty good site Gates if it helps anyone https://www.gatestechzone.com/en/pro...-failure-signs and secondly I never knew that there are wear indicator/marks on the tensioner to help tell if it is putting enough tension on the belt. see pic.

I'm hoping to get a vid/sound clip of what I'm dealing with. Maybe it will help someone else. Gotta say this isn't my first belt squeal issue. Had the problem with two 4th gens and a 3rd gen. Those were pulleys and one was a belt. I'll post a follow up either way. Thanks reading and any feedback is welcome. I'm humble.

4th Gen Tensioner Wear Indicator

 

You never mentioned the accessories like alternator or power steering pump. Are you convinced one of these isnt the culprit? Just from your post alternator would be my guess.