Jumping on this recent thread as working on my horn. I have a 6 volt positive ground ‘51 GMC.

I just tested the relay and the horn and got the horn to honk by touching a wire from the “S” of my relay to ground.

Once upon a time my horn button worked so I think my issue is the wire going down the steering column. (it’s the last piece of cloth wire on my truck…everything else is replaced with plastic insulated wire).

Any tips on running a replacement? Should I use #10 AWG so the ground is good? I’m worried my old wire will break as I pull the new wire through.

Also, I’m not sure I’m Hooked up correctly. Here are some tests I’ve done:
- I tested my relay as per this site ( https://devestechnet.com/Home/ADWiringSystem ) and also bypassed my horn button to get the honking
- There are 2 wires on the horn, one is connected to the hot wire of the voltage regulator and the other is grounded.
- I disconnected both wires and tested ground from the horn body (none) and from each of the terminals on the horn (none)
- I found continuity across the 2 terminals of the horn
- wiring diagram shows that I should be getting hot from the Ammeter but I’m getting it off the voltage regulator. Should I change this?

1951 GMC with positive ground. Engine is a ‘54 Chevy passenger car (Serial Number 0024472F54Z) with a ‘56 head (casting code on top of head 3836848 GM 4), Casting Code (on passenger side on side of head B56 848 850)