Belt Squealing

I have a F-150, 1995, with 130,000 miles and has a 4.9L engine. I have a belt the is squealing only when the engine is cold. After about 10 minutes of driving it goes away.

This engine was bought used and was working fine for about 7 or 8 months. Then it broke a belt on the way to work. I replaced it with another one and the next day I broke another one.

So I took it to a shop. He suggested replacing the belt tensioner. In which I did and bought another belt. This is when the squealing started. But no more belt breakage or slipping. It has been doing this for about 3 months now.

So I have tried cleaning the belt with a wire brush. Cleaned all the pulleys with a wire brush. Help a little, but the noise continue and just as loud with a cold engine and I have even bought another belt. A better one, if there is such a thing, more pricey anyways.

So took it to another mechanic, he told me the alternator pulley was bad, so I replaced it. It worked fine as soon as I started the engine after repair. The next morning it was back, the squealing. But the noise does goes away a little sooner.

The alignment on the AC compressor seems to be a little off as I have shown several mechanics. But all the shops I have taken the truck to didn't seem to think that was a problem, but nothing seems loose.

All the other pulleys seem to be ok, as they are free spinning and not rough or have any movement.

The automatic tensioner seems plenty tight. But sitting here thinking, didn't have a problem before the new tensioner, then again, not sure why the truck started throwing belts in the first place.

I really don't want to try the hit or miss method, trying to fix this thing. So any help would be greatly appreciated.

Thanks
Jearl