I have been following my 1942 manual and have sorted out my wiring to the starter, brake switch, dome light and taillights. Success all around. now comes the final part, the horn. There was a wire connected to the relay but it went nowhere, just hanging in harness. I have found a piece of wire sticking out of the column near the steering box on the bottom side. It had a plastic cover around it. Does this piece of wire run up the column to the top bearing? Can I pull out the bearing and run a new wire? Thanks

 

Here is a simplified horn wiring diagram thanks to Camaros.net
Basically the horn switches to ground so that when you push the horn ring on your 47 it completes a ground circuit and allows the horn relay to close and send power to the horns. The horns have their own ground. So its a good bet the wire coming out of your steering gear is that ground wire and probably went to the horn relay.
boschrelay.png
You can check that wire going into the steering box with a VOM. It should show a resistance. if it does not you have a short somewhere in there. If it shows a resistance and then you push the horn ring the resistance should drop to zero as the ground is completed.
Caveat: I don't guarantee this is 100% accurate and hope others with more knowledge of stock wiring in our 40s Oldsmobiles will chime in. My own 47 has been modified and has a later GM steering column and I had to rewire from scratch. But I do know on virtually all the cars I've worked on the horns switch to ground and that ground completes the circuit in the horn relay allowing power to go to the horns themselves.
Jerry

 

My relay is the original model with only 3 tabs. Horn, battery and switch. I have it figured out now but i need to know if that broken wire coming out of the bottom of the column goes up to the upper bearing. I have the steering wheel off now so if anyone knows if I have to pull the upper bearing out let me know. Thanks.