belts squeeling

1997 Caravan 3.3 the belts are making a terrible sound. Is there a way to tighten them? I was told by a backyard mechanic to be careful not to tighten them too much. How much is too much?
Just had the steering rack replaced, fluid everywhere, thought that was it but motor is clean and dry

Your 3.3 ltr uses a single serpentine drivebelt that is automatically adjusted by a self adjusting belt tensioner pully assembly. No adjustment is required or available. However, if the tensioner is bound up, not providing enough tension, you may need to replace it. Also if the belt is soaked with power steering fluid, you'll need to replace the belt and clean all the pulleys.

Try this technique to narrow down the source of the squeal:

http://free-auto-repair-advice.blogspot.com/2007/07/diagnosis-squeaks-and-squeals.html

thanks guys! Never found a place to get this much information so fast and that is so helpful!!!
I hate taking my van(s) to a shop to be told how much it will cost and how many things are wrong. It's nice to have the help from knowledgable people, not looking at the almighty dollar
A great help! Thanks again!!!!!