Another problematic horn...

I have searched and read through many of the previous post on this issue...my horn does not sound when the buttons are pressed, although the horn does sound if I press the lock button with a door open, so I know the horn itself works. Here is what I have done and checked...I swapped the rotary coupler and that did not help. Continuity checks on the coupler shows OK. The airbag light works, but is not constantly on.

I have a Haynes manual with the electrical diagrams...not the easiest to trace through, but it is something. It looks like the earth connection is passed up through the steering column to the coupler on PIN 4, goes through the coupler to the switches, back to the coupler and out of the column on PIN 3 to the horn relay. Is this correct so far?

I have changed the radio because the old radio did not work at all, but the horn did. The old radio is long gone, it was months ago and I never use my horn, but it came up at my NCT. I have read about the radio being a cause of issues, but there does not seem to be any good solution, other than put the old radio back in. If putting the old radio back in fixes the problem, then we should be able to jump a connection or earth to make the same "fix"...right?

Any help would be appreciated, I love turning a wrench, but I hate chasing electrical demons.

There is a coil in the steering wheel which carries the horn signal and one of the tracks is probably broken. If you have or don't use the volume control buttons on the wheel you can re-purpose one of the tracks for your horn.
Or you can replace the coil thing which I can't remember what it's called.
But it's a common fault in Freelanders.
Edit
Oops, I just reread and spotted you replaced the coupler.
Did you use a new one or 2nd hand as 2nd hand could have the same fault?
Did you make sure the coupler was centred correctly when fitting?
Is the airbag light now on?

The coil thing would be the clockspring.

Continuity checks on the coupler shows OK.

Click to expand...

Did you check the actual horn buttons were working during those checks?
Have you tried manually triggering the horn signal through the steering wheel connector plug to verify the wiring from there to the horn?

I did use a second hand one, only one readily available...turns out that while all the connections on the coupler passed a continuity test, pins 3 and 4 did not pass a load test. Swapped pins 3 and 4 to the 1 and 2 position and I have a working horn now. Thanks for the help!