Thank you rich, I found this from a Poster
quote, 74 Argosy, There is a flat harness coming out of the column, the wires are all bonded side by side and go into a connector, it could be flat or semi rounded. This is for the horn, blinkers, etc. that run off the column. It has to be there if your blinkers are working. The horn wire isn't necessarily green, when you find the connector go by the location, my wire is black.
Have you tried the horn to be sure it is working? They don't last too long. I would run a jumper from a good 12v
to the horn before I started on the dash, a lot less work.
Service manuals are good to have. Did they give you a place to get one? I am not sure how long they print (or stock) them.