sounds like your on the right track. your going to be looking for something
making the belt track off or not hold proper tension. if the idler is
leaning then the belt will track out of correct position and squeal or
chirp, if the tensioner is locking up then the belt will do the same. simple
check grab the belt near the tensioner (rh/passenger side of the truck
between the alt and crankshaft) give the belt a firm pull the tensioner
should deflect and quickly return. if you are unable to move the tensioner
by pulling on the belt or if you move it but it doesn't readily return then
the tensioner is locking up in its pivot and is not keeping correct tension
on the belt. also check your power steering pulley it should be pressed onto
the power steering pump shaft such that the shaft and end flange of the
pulley are flush if they are not then the pulley has walked off the shaft
some and could be a cause, I've seen this a time or two. hope this is some
helpful information.