serpentine belt

May be out of alignment with your pully's and belt wheels due the age of your car and wear and tear generally cause pulley's to get out of line. If thats the case I would try replacing all of them before and recheck for alignment before installing a new belt. If your still having a problem check with your local mechanic for specs, or your Dodge Caravan 1996- 1998 Mini-vans Haynes Automotive Repair Manual based on a complete teardown and rebuild #30011 Haynes.