Originally Posted by Alan

Here is the controller I built for this. It has a standard weather resistant relay and fuse and a cable connector (all weatherpak types) all integrated together

Internally there is a small (simple) custom designed circuit driving the loud horns via a relay after a delay.

Inputs are (30) Power, Ground and the stock horn output - used as a trigger input (also still feeds the stock horns). The outputs are a ground and horn output pair for the supertone horns.

When you hit the horn button you get the stock horns for approx 1/3 second - then the supertones kick in and stay on, as soon as you release the horn button - all is silent.

You can repeatedly tap the horn button for <1/3 second and only get the gentle beep beep - lean on it and it gets loud fast - pretty intuitive to use.

Now to install it.

Alan