belt tensioner on 98 Grand Voyager

I've gone through 3-4 belt tensioners in the past 7 months. They'll
work for varying amounts of time (varying from a week to a couple of
months) and then they start squealing again. They don't do it all the
time (most often when my wife is off driving it, least often when near
a mechanic). we've tried both replacement brands and one from Chrysler.

Any ideas?

 

It might help to know what engine you're working on. And how you
determined it was the tensioner at fault. My idea is that it's really
not the tensioner making noise...it's either the idler or the AC
clutch, or maybe even the alternator.

 

The engine is the 3.3 (as I recall). The mechanic used the broomstick
method of stopping the tensioner and having the sound go away. He said
it was the bearing in the tensioner. I also went through several AC
compressors last summer before they found one that didn't screech after
a few days.

 

since it's a van i would look to see if there is still a drain tube and
drain coming off the bottom of the wiper cowl
if it's missing then water may be getting on the belt and it's slipping
and making noise

 

Belt alignment is the key to having the belt stay on, also make sure there
is no oil leaks, coolant leaks and the a/c drain tube is in place and not
leaking on the p/s pump pulley. If the power steering pump has been
replaced, it may have had the pulley improperly installed.
I don't think you needed that many tensioners in that short of period..
Have someone else look at it before installing another belt or tensioner