94 Jeep Cherokee Wandering Belt

Had a howling noise that sounded like a bearing going out. After searching, I see that the fan belt is actually sliding on the pulley. Looks like a vertical alignment problem. It could be the idler pulley, the fan pulley or possibly the lower Crank (?) pulley knocking it out. I can see the belt sliding approx 3/8 to 1/2 inch . At idle it sits closer to the engine, as rev it it seems to line up. All this action certainly means the belt is shot. But could be idler too.
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I went thru a few things to check it out. I looked at the power steering unit, pulled off the belt and check if there was any obvious play in each of the pulleys. All seemed ok. The idler seemed rough running but no wobble of play in it. I will replace the idler anyway since I bought one. The belt has no damage to it. It was changed about a year ago. So it's just been wandering on the fan pulley. Went to the Crank pulley and the dampener .and it feels tight. There are some obvious small plastic cracks on the outside. friend suggest pulling on the pulley and look for separation between the inner, outer, and rubber ring in between. Felt and looked tight. After I change the idler anyways, I'll look again. But could the crank dampener still be bad? Suggestions.
Thanks.

I solved this problem awhile ago. Thought I'd post the result. It was the idler due to the bearing sticking. Runs like a champ now. Learned a few things how to check the harmonic dampener with a timing light and white out. And a few other tricks to make sure misalignment of the other units like the power steering etc are critical. Long story short. Solved the problem