While driving I hear a LOUD squealing noise coming through the vents. When the squealing starts my rpms go up some but when it stops they go back down. What is my problem and how can i stop the squeal.

 

Is this with ac/defroster turned on or off? I'd definitely check belt tension. Can you easily twist the belt 90*? If so, I'd tighten it so that it's not so easy to twist the full 90*.

 

it is with defrost on and where do i tighten the belt up

 

Get it to do it and then turn the defrost off, see if it goes away. Or turn the a/c on and see if it does it too. I'm just wondering if it's your a/c compressor clutch starting to slip.

As for the belt, you've got I believe 3 bolts on the power steering pump bracket that have to be loosened up so that the whole bracket can move - 2 on the front (one up top and one below) and 1 on the back side that is reached from the bottom side of the vehicle. I want to say they are 13mm? But then you have an adjusting bolt under the pump (look to the left of the lower radiator hose) that will move the power steering pump, causing the belt to tighten or loosen depending on which way you turn it. When you get it set right, tighten the 3 bolts that hold it all in place.

I'm thinking that maybe newer XJs have an automatic tensioner, but older ones use the method above. It's really easy once you find your way around, but man I sure loved the automatic tensioner on my '87 Mustang 5.0!

 

My Jeep is a 98 and it will go off eventually even when the defrost is on. Yes i can turn the belt 90 degrees.

 

If you want to know if its the belt here is one simple solution:
pour some water on it.

if the squeal stops its the belt, if not its something else

the only reason that I can think of that the BELT would cause the rpms to increase would maybe because its slipping and not having the extra friction and tension of spinning all the accessories on the engine?