Alternator squeal? Maybe?

[rfbasshead]

Ok so I have a mechman 240 on my 00 Tacoma. When I first got it and put it in it didn't sqeal at all not on start up not ever. Now, also, when I put it in I had over tightened it as well which ended up in the belt snapping and leaving huge chunks of gunk on all the pully that the alternator belt ran on. Prior to it snapping it started to squeal and the ribbs along the belt were pretty much gone. So I got it home and was to lazy to completely clean the pullys. So i just ran a wire brush along the groves real quick and slapped the belt on. And off I went. I drive the truck all day for work putting like 250-300 miles on it daily, so the next day the belts were squealing everytime I gave it gas up until i got going. That lasted like 2 days until I coldnt take it anymore so I took all the belts off cleaned it got a new alternator belt and tried again. That Worked but only if I dont crank the bass and as soon as i do the squeal came back. So the next day i tried again. Took all the belts off and cleaned every groove. (The second time was kinda halfed ass to) but after the third time I wasn't going to do it again so I cleaned it right. Used wire brushes and small screwdrivers till they were all completely clear. Got another new belt and slapped it back together and gave it another go. This time nothing for half a day. I could bump my music at a light and take off when it turns green and not have to worry about the belt squealing. Basically my problem is my alternator belt squeals only when my voltage drops to like 12.5 (which is usually a stop light and my music is up) and I give it gas to go it slips. If it stays above 13 it won't do it. What could be the issue? I've checkd that it's not to tight or loose the pullys don't feel lose. And I'm out of ideas..

[Ahmed Johnson]

Is your alternator aligned properly? I had a problem kind of like yours. It turned out my belt tensioner was no good.

[rfbasshead]

Maybe? Idk. I know it wasn't doing it before. And I did have to get a braket made. And when you say belt tensioner you mean the screw that actually pulls the alternator tighter and loosens it?

[Ahmed Johnson]

I have an automatic belt tensioner that you use to get the belt on and off. I don't know if you have one. You should check all the pulleys for movement

[rfbasshead]

Like try and move them back and forth? Not spin but like wiggle?

[Ahmed Johnson]

They are going to spin, but if you see any wiggling you got a problem. Get someone to step on the gas while you look at everything on the belt.

[rfbasshead]

What trips me out is it only does it when the voltage drops to like 12.7. It can hover at 12.9-13 and nothing. And when it does squeal the only way to stop it is by pausing the music. Literally pause not turn it down.

[Ahmed Johnson]

The voltage could be dropping because the belt is slipping and not spinning the pulley on the alternator enough

[Ahmed Johnson]

What trips me out is it only does it when the voltage drops to like 12.7. It can hover at 12.9-13 and nothing. And when it does squeal the only way to stop it is by pausing the music. Literally pause not turn it down.

Your alternator is cussing you out for maxing it out without the pulley spinning properly. You could send it back to mechman, but you might be out of shipping and time if it they don't find a problem with it.

[rfbasshead]

No it always did that. My idle isn't high enough. I turned it up already. When I first put it in it wouldn't charge at all during idle. So I turned it up to where it'll stay above 14 with just the normal electrical (windows heater, ac, headlights)