Larry,
In looking at the referenced accessory book here:
1957 Accessory Manual , the diagrams on pages 177 and 178 are kind of misleading.
Shows what looks like only 3 wires from signal switch cup, threaded through the column openings at top and bottom, and then connected by a "3-way" connector under the dash.
In actuality, the wires from the signal switch cup are 6 in count in a flat harness that is fed through the steering column openings (must be done with the plastic 6-wire connector removed form the wire pin end of harness).
Once the 6-wire flat harness exits the steering column housing, the 6 wires male prongs are inserted into the plastic harness connector plug (must pay attention to column to dash harness color coding to make sure they are correctly placed), which then plugs into the 6-wire connector under dash harness. That connector should be close to the lower section of the steering column so the two can marry up.
I have attached pictures captured from various online vendors/sources of currently available reproduction harness components that may help you visualize how they are installed and go together.
Hope this is of some help in getting your install completed???
Good luck!
