WARNING: This page is about a different car, the 2003 Dodge Intrepid, 2003 Chrysler Intrepid, 2003 Chrysler Concorde, and 2003 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Wiper Erratic Operation In Intermittent Speeds - Diagnostic Procedure (1 Of 2)
Courtesy of DAIMLERCHRYSLER CORP.
Fig 2: Wiper Erratic Operation In Intermittent Speeds - Diagnostic Procedure (2 Of 2)