Another neat and clean solution by Orrie! Nice.
I forgot to mention in my first post that a '64 - '66 truck that came with washers would have had a push button in the center of the twist wiper knob. When you push the button it engages the washer (originally built into the wiper motor) and forces the knob to twist to the low speed setting. You can drill out the TF knob and install it on this switch for a clean install.
