I got my Haddley Air horns working today. I think my neighbors are petitioning an eviction.
I had to do some troubleshooting. Found the air valve and electric relay. I detemined that I had supply air to the valve.
I determined that I had electricity to the valve when horn button was depressed.
I had to dismantle valve assembly. The magnetic coil was working but the plunger in the valve body was seized. Broke it down, sanded the plunger a little to remove corrosion. Lubed it up and re-assembled. WORKS GREAT and very LOUD!