Electric Wiper Problem

[BuickNut]

Howdy......I have a problem with my electric wipers on my Dad's '86 Buick. We replaced the wiper switch, wiper motor, and regulator in the system a year ago. The same problem now popped up out of the blue but with a new twist. The wipers were working on the intermittent mode when they all of a sudden stopped. The only wiper function now operating is the hi speed wipers....the washer mode doesn't work either. It seemed previously we actually cured the problem by replacing the last thing possible - the regulator. However, I don't recall that the washer mode was inoperable last year. Any slants on this ? Guess I don't want to do the complete system switch again as the parts are still kinda expensive... Thanks.