Sqealing belt

I have a 91 tempo and i put an alternator on it over spring break. About a week later the belt started sqealing and i just ignored it. So a week ago the car died and the belt was snapped and worn down the sides. So i put a new one on and now its sqealing. I have tried belt dressing and adjusting it now im out of ideas. Its too late to replace the alt and i dont want to pay for a new one. Any ideas?

possibly the new alternator has the wrong size pully on it or it is out of alignment, or (if its a non-serpentine type) you are over or under tightening it

My Topaz had the same problem, and after multi belts it turned out being the alternator bracket was broken.

We had to take the alternator and bracket right off to find the break.