94 Blazer S-10 model, 4.3L V6 w/AC.
Have factory service manual.
During changeout of power steering pump, manual says to ease up the belt
tensioner by loosening the center bolt and turning the tensioner
counter-clockwise.  The belt tensioner's pulley rides between the alternator
and AC pulleys, and pushes the serpentine belt straight down between these 2
pulleys.  Attempting to rotate the tensioner counter-clockwise or clock-wise
just increases the tension.  At mid-travel, least tension, cannot remove
serpentine belt either.  That's the way I found the tensioner to begin with.

Left with no choice but to remove the bolt holding the tensioner.  And,
sproing, out pops the tensioner, the bolt and washer, a heavy duty spring
and its housing.  Later, I found a ball bearing around 3/4" in diameter,
does this go to the tensioner as well?  Noticed a few metal shavings at the
tensioner's mounting bolt mounting location on that housing.  May be
stripped at the beginning of the thread of this mount location.  Should I
replace the tensioner?

Power steering pump replacement went okay.  PITA removing and installing the
pulley for that though.