Broken Tensioner?

[Fordsfor4X4ing]

I have a 1997 4X4 Explorer, As I was speeding up on the highway yesterday on my way home my drivebelt started squeaking. I pulled over at the next gas station, turned my car off and looked under the hood. I noticed the drive belt wasn't tight at all. I decided to just get a better look at home so I got back in and started it back up. Since the drivebelt wasn't tight my alternator wasn't getting power so I drove home with basically no power steering. I checked it out today and the belt is fine and it didn't slip off anything. The tensioner is just not keeping the belt taught. And If i'm not mistaken these have an automatic adjustmant so maybe the spring for that is broken? What do you guys think? and how much do you think this will run me?

 

[Colo4X4]

I actually fixed my wifes last winter late at night. The part cost me I think $80 at checkers ( which they had it in stock) and it took me about 30 mins to put it back in. Real quick and easy to do. Same thing with hers the spring unit had failed, the belt stayed on but no tension on the belt. Didnt even need to jack up the car but might need a helping had to pull it back far enough to get the belt back on after you get it bolted back on.

 

[dogfriend]

If you let it go long enough, it will eventually grenade itself and blow into pieces under the hood. That was what mine did after squeaking for a week or two. I got a replacement tensioner and a replacement belt, but the belt was still ok so I carry the new one around in case the old one snaps.