Hyundai Repair: 2001 hyundai sonata a/c clutch, hyundai sonata, proper tension

Question
I have a 2001 hyundai sonata v-6, 2.5 litre engine that squeals very loudly when the air conditioning is turned on. It appears that the squeal is coming from the clutch hub and pulley and bearing assembly. I also noticed that the outer edge of the serpentine belt, which is fairly new, has started to fray. Would the clutch hub and bearing assembly going bad cause this to happen? Could something else like the auto tensioner cause this to happen?  If so, how would I check the auto tensioner to make sure that it hasn't gone bad? Any help would be greatly appreciated. Vic  

Answer
There are several possibilities here:
1.  The belt is too long and cannot be tensioned properly.
2.  The tensioner doesn't keep proper tension.
3.  The compressor is locked up or beginning to lock up.
4.  One of the pulleys is improperly aligned.

Start with scenarios 1 and 2 since they're the easiest to check.  The tensioner has an arrow and a series of lines on it.  The arrow should point between the first and last lines.  If it doesn't, that's an indication that the belt is the improper length or the tensioner is failing.  Next, with the engine off, perform a physical inspection of the tensioner.  Flex the tensioner (with a 3/8" drive ratchet or 17mm open end wrench, depending on the tensioner) and make sure it springs back.  Also make sure the tensioner has little side-to-side play.  If it doesn't spring back properly, or it has excessive play, replace the tensioner.

Presuming you'll need to replace the belt due to the fraying, check how easily the compressor turns while you have the belt off.  Grab the center part of the compressor pulley and attempt to turn the compressor by hand.  You should be able to turn it, but it should have some resistance.

Although this doesn't typically cause a loud squealing noise, I included pulley alignment because you said the belt was frayed.  Do your best to look in a straight line along the pulley edges and verify they all seem to be in a straight line.  If any appear cocked, they'll require further investigation to determine the source of the problem.