One problem related to wiper has been reported for the 1998 GMC Sierra 2500. The most recently reported issues are listed below.
Windshield wipers began to fail suddenly on and off while driving in the rain and eventually quit working all together. I checked with the dealer for recalls and found that there were recalls for this problem on chevy & GMC trucks from 1994 to 1996. My truck is a 1998 but it was built in 1997. I waited for the recall to be extended however I finally spent $60. 00 and replaced the defective part. I know 3 other people with 1998 chevy/GMC trucks who have all had this problem. One resulted in the death of a child and the imprisonment of the driver who was unable to file a complaint.