Just so I understand, you put the old belt back on and it has not shredded? If that is the case, then it was either the belt or it was ridding on the collar of a pulley and it shredded it. That is not uncommon when it rides on the collar.
Here is a guide that walks through a replacement. Clearly that may not be needed for you but others that visit this page may need the additional info.
Also, if the belt was incorrect it would fail pretty fast as well. I would just get another belt and install it just making sure that it is centered on all the pulleys.
If you have not installed the old one, I would do that and make sure it doesn't fail as well. If so, then I would agree the tensioner is the most likely cause.
Friday, November 20th, 2020 AT 5:07 PM