Whoa, make sure you have loosened the big 19mm bolt in the center of the tensioner. The adjusting nut should then turn easily to release tension. If you are releasing tension, the long adjusting rod should be screwing up into the adjuster nut.
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.