One of the things I was disappointed with on my Seneca is the really wimpy electric horn. My Focus toad has a far better stock horn! So I embarked on a mission to make things better by installing a set of real air horns. Since our Senecas have an onboard air system I decided to tap into it to accomplish the horns. And while I was at it I also decided to add an air accessory air port so I could fill my own tires or for whatever else I might need compressed air for.
To accomplish the air side I installed a 2.5 gallon auxiliary air tank fed from the chassis "wet" tank through a pressure protection valve. That valve is to ensure that the horn and air fill can never completely deplete the main air system. Then I ran an air line out of the new tank to the air horn mounting location on the right frame rail near the hood hinge. There the air line tees into the air fill regulator and to the horns themselves. Out of the regulator I have a female air quick disconnect. The horns are also mounted here behind the bumper for protection.
To operate the horns I still use the regular steering wheel horn button, but the circuit goes through a dash-mounted Electric/Air horns switch. So I can select either horn I want; a gentle electric "beep", or the sound of a locomotive bearing down! The selector switch is genuine Freightliner used on an American LaFrance fire truck, matches the other dash switches perfectly. I used the same switch connector on the back of the switch that Freightliner uses, so the wiring looks like the factory did it.
To view more pictures of the components please see the album here: http://www.jaycoowners.com/forums/me...lbums1069.html