Squeaky belts

If you can't tell what one it is find a decent size tube you can hear into. Put the other end near the pulleys one by one and ull find your loud one quick.

 

None of that stuff is gonna work. It wants some of your blood.

 

Take a good close look at any/all ribbed pulleys. The small v-type grooves can get a build-up of embedded belt rubber and other trash, stuck to the groove bottom & sidewalls of each groove. A wire brush will clean them out.
My first thought was an idler pulley, but it seems you've inspected those already.

 

I agree with Cajun, try cleaning the grooves on all the pulleys, enough build-up the bottom of the pulley grooves will keep the belt from seating properly and let it slip. If that doesn't work try replacing a couple of the older factory pulleys, most people will laugh at me, but a rubber belt will wear the grooves on a metal pulley enough to let them slip. If I remember correctly your Acert is just as old as mine so if there is deposits in the grooves, they will probably be petrified, might be better off to replace it any way.

 

Get a spare belt. Turn radio up

 

Everybody already mentioned everything i would have said although some pulleys will spin free when you have the belt off, and bind a little under belt pressure, I would remove the belt again and look for flat spots on the pulleys and really take a good close look/ feel on each pulley and a wiggle from side to side --otherwise it could just be a inferior belt ?
Another thought is to just spray something like wd 40 (belt dressing would be better ) on the belt --and see if the noise instantly goes away then comes back shortly--then suspect a pulley !

 

They call it Belt Conditioner, its sells at Autozone,Oriley Auto parts, Advance autoparts and Napa. On Internationals ive seen the idler pulley slows when going bad and causes the belt to squeak.

 

So they dont wobble at all? I've always heard replace them when you replace the belt.

Squeeling means some rubber is rubbing over some metal, so check all your componncts and make sure they spin free ly and the grooved belt is sitting it the nochs correctly.

 

I've got a squeak now too after replacing mine. All pulleys spun well, but the belt had to be put on in really really cold weather and it was very stiff. I think some sort if rubber conditioner would be in order since it just started with the addition of a new belt. That implies belt is the problem somehow.