Diagnostic Aids
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
If the drive belt(s) repeatedly falls off the accessory drive pulley(s), this may be caused by pulley misalignment.
An extra load that is quickly applied or released by an accessory drive component may also cause the drive belt(s) to fall off. Verify that the accessory drive component(s) are operate properly.
If the drive belt(s) is the incorrect length, the drive belt tensioner(s) may not maintain the proper tension on the drive belt(s).