I've got mine hooked to my stock horn.
System is comprised of a ViAir 2.5 gallon air tank, ViAir pressure shut off relay, ViAir 15% duty cycle compressor and a horn off a delivery truck.
Tank, compressor, and relay are where the spare tire used to be.
Air lines, and electrical wires are then ran up to the cab/motor bay.
I have a wire spliced into the stock wire that goes to the stock horn, that runs straight to the inline air solenoid. So the stock electrical signal is what opens the solenoid triggers the air horn.
Compressor then comes on at 85PSI (even as low as 50 PSI will run and be plenty loud enough for most horns...but 85-110 is best). Then the compressor shuts off at 110 PSI.
System hardly leaks, about once a month it comes on by itself and charges the air tank for max of 1 min. Even if I use the horn, the compressor hardly ever comes on. The horn itself just doesn't use that much air.
Plus from the system I have quick connects plumbed, and I can fill my tires up from 15PSI to 35PSI in about 20 min.
I'm looking to convert to a ViAir 100% duty cycle compressor later on, to speed up the time it takes to air the tires up, and to run air tools
True 6" lift, SJ brackets-coils-leafs, JD RBV/EB Buckets, Bilstein 5125's, Lock-Rite Front, No-Slip Rear, 1-ton SuperRunner Steering, TJM T13 bumper/winch, 10" LED, 33x10.5 KM2's, Bolt on Thread http://www.therangerstation.com/foru...ad.php?t=75235