what does it mean when my alternator squeals and when I take the positive wire off it stops squealing?
Please tell you didn't take the positive cable off with the engine running, cause if you did the chances of damaging the vehicles electronics just skyrocketed. Now to your problem, first check the belt and the tension, if the belt is frayed or cracked replace it, if it is loose then the tensioner is going bad, fairly common problem, if that checks good then make sure of the pulley alignment is correct, if all of that is good then get a mechanics stethoscope and try to pinpoint the exact location of the noise, it could be an idler or even the alternator itself. Make sure your battery and charging system are up to the job, might get them tested.
I agree with tennisshoes do not remove positive terminal when vehicle is running can mess up computer it's not like in the older vehicles that do not have computers you can test those vehicles that way. To check to hear if alternator bearing are bad with belt off give alternator pulley a spin with your hand should make noise if bearings are bad. Check other pulleys the same way by giving them a spin.
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