5.0 motor help

:cry: having problems with my serpentine belt staying on . i put on the upr smog pump and a/c eliminator pulleys. does anyone know what i can do or why the belt is coming of . could it be the belt tensioner.the power steering pump has some movement in & out is that normal also the tensioner will move by hand :cry:

I don’t think the tensioner should move by hand, don’t you need to use a tool to loosen or tighten it?