[Your41Plague12]

I'm not sure about why they do a sweep like that. So it never did it with the factory dash switch, but once you installed the intermittent dash switch and the box under the dash it began to do it?

And as for the wipers being slow, that's just the way these old tanks are. My 83 had two speeds, slow and slower. My neighbor's 55 chevy wagon with factory vacuum wipers has wipers that move twice as fast. It's pretty pathetic.