On my 67 El Camino with 2 speed wipers, the only way I can get them to work is by pushing in for the windshield washers. If I turn the switch to the right to speed 1 or 2 it won't work, only when I use the washers. I took the washer apart and it looks great inside. I also sanded the contacts a little but still no help. Any suggestions?

What happens if you:
Turn the key on.
Turn the wiper switch on.
Take a piece of wire. Touch one end to the wiper switch body and the other end to a good clean dash ground.