I just traced the wires from the iDidit column and I found that the blue/yellow wire is connected to the black column wire, which is correct.
No, it's not.
The Blue w/yellow stripe is for "power out to the horn" so it must be connected to the #87 pin on the relay.
The Black wire from the column (if it's the horn button ground) should be connected to pin #85 of the relay.
The yellow wire (460 on the diagram from Oldtimer) on the horn circuit isn't connected to anything but has 12V+.
Yes, it's connected to the headlight switch. It used to go up into the original column, to the 2-pin horn button, then back out to the horn via the Blue w/yellow wire.
For a '69, it's getting power from it's connection to the headlight switch, which in turn gets it's power directly from the large Black wire in the harness.
For '74 and later Broncos that used a factory horn relay, the Yellow wire was under the hood and connected directly between the horn relay and the starter relay/solenoid to get it's power.
You can use your existing Yellow wire to power your new relay, if you don't already have a permanent connection between the battery and pin #30.
But if you already have that dialed in, you can cap off the Yellow wire and keep it tucked safely out of the way.
Paul
