98 Century Wiper issue

'98 Century Custom windshield wipers will only work on the high speed setting. The wipers also do not park when turned off, they just stop in any position on the windshield.

Could a bad pulse board be the problem?

Also, does anyone have any ideas how to deal with stripped off knurling. I have temporarily fixed this problem by removing the arm, and putting a large external star lock washer under the arm with a smaller external star lock on top of the arm then making sure the nut is nice and tight.

Yes the pulse board is a good possibility.

The wiper stud knurling is not stripped off. It's just filled with aluminum from the wiper arm itself. Remove the arm from the mounting stud, then use a pick or something with nice point to clean out the studs. You will be scrapping the aluminum from the splines, then reinstall the wiper arms.

David