New England Tour

I would check the battery terminals. Poor contact on the battery terminals will cause the alternator to want to go to full output, which would put a strain on the belt. Voltage regulators are black or white... i.e. Good or Bad, no in-between!
Loose belts squeal when they slip, and over tightened belts put a strain on all the bearings behind the pulleys that the belt drives. This is why the factory service manual give you specific tightening information for each belt.
Since you didn't say what the vehicle was, I can't comment further, but the blue paint makes me think that it is a Pontiac. If that is the case, and the car has over 70,000 miles on the engine, then you should consider changing the timing chain. It is a problem on every Pontiac with higher mileage. When they fail, they can do a lot of engine damage, that is expensive to fix. I usually check the timing chain when I have everything out to do a water pump. Once you are that far into it, the timing cover is only a few more bolts.

 

Besides dirty battery terminals, a defunct regulator will make it go 'full-field,' which will put a heavy strain on the belt due to slippage overheating. BigBird's right; replace the alternator and have the battery load-tested. Hopefully, the battery was not affected by the overcharging.

 

I talked to a local alternator and starter shop. My volt meter in the car holds right at 13-14 volts while driving, and the shop really didn't see why AutoZone claimed the voltage regulator was faulty.
It looks like the reason my belt was failing was it was the wrong belt number.
I still plan on getting the alternator looked at again, just to make sure, but after getting the right belt number, I haven't had any more issues.

Thank you again everyone for your help!

 

Jeez. Leave it to a bunch of VatoZoneJobs to screw things up. Good to hear you're back on the road.