Intermittent Wipers have mind of their own.

[uncle]

New to this side of board but is it common problem for int wipers to not function properly on 88 up ( this is 90 I'm working on). One time works fine next time it may go non stop for couple minutes. Wipers will stop in middle,top3/4of windshield. Relay under hood a fix? Any help or suggestions would be appreciated. Doesn't matter what position you put it on either.