Why does the serpentine belt on a Dodge Grand Caravan keep coming off. Is there not a guard?

Answer 1

There's likely a misalignment of one of the pulleys. Most likely it's the belt tensioner unit; I've had 3 fail over 4 Caravans and 600k miles. These tend to have their bearings fail, and/or their tensioner spring freeze. The first will result in a misaligned belt, the second in reduced belt tension. Either will cause the belt to come off. Remove the belt and "exercise" the unit. If it doesn't rotate with full, free motion and good spring tension, or if the pulley wobbles, replace the unit. It's hard to get at for R&R, but not expensive.