Truck (and dog):
Here is how it is wired. The left toggle controls the compressor. The right switches between the stock horn and the train horn. Both are activated with the regular horn switch in the steering wheel.
The spare tire has made its home in the bed because something else has taken its place. A jack fits perfectly underneath. The 5 gallon tank and Viair 444c compressor are screwed to plywood and bolted to the bed. A 5/8 ID Continental air hose runs to the horn.
The horn faces forward and is activated with a solenoid located directly above. There was very little room to work with.
I’ll probably add in more details later.
Edit: fixed the size of images
