March 20, 2009Ok here is what I''m looking to do I have an ''08 F-250 and I want to use one of my auxillary switches in my dash to power my compressors. Then I want to use another one of my switches if its possible to switch the horn from stock horn to the solenoid for the air horns. So when I have the switch on and hit my steering wheel it will only turn on the air horn rather than both horns....My problem is I dont have wiring diagrams for my truck and I dont know where to tap into the auxillary switches in the dash
Forums : Electrical : Hooking up Air Horns (5019 Views)
March 21, 2009the other thing you can do is disconnect your factory horns. then when you push the steering wheel you can listen for the relay clicking. from there you just need a test light and another hand to push the horn till you find the right wire that needs to be looped into a new d.p.d.t. relay so you can install the airhorn set up.
that is how mine is done.
March 21, 2009man he aint askn for someone to tell him to do somethn totaly diffrent(tco1979)!!
if he''''s askn about air horns , he wants air horns, not some speaker/horn, ish i could help but you might be able to google some wire schematics, should be pretty simple if you find em. sorry for not bein any help.
March 21, 2009Sandman, unfortunately, the factory switches will not allow you to do what you are after without adding a relay just for directing where the signal goes. Your best bet is to get a single pole On-Off-On switch. Doesn''t need to be big (anything over 1 amp in rating is plenty. The wire running from the steering column for the horns grounds when you press the steering wheel. So, the wire running to the fuse box gets connected on 1 end of the switch, the wire running up the steering column to the center post, and the ground wire to feed power to the air horn relay on the other outside post. The rest of the setup is just like wiring up a standard air horn setup.
If you need more help, just hollar. I''ll do what it takes to allow you to understand what I am talking about.
Chris "Thermo" Coleman, Nukie the radioactive 97 Ford X, and K''Re Ann the 03 Jag X
March 24, 2009got it done i ended up unplugging the horn and tapping into the 12 volt wire going to the normal horn in order to still use the steering wheel button to open the solenoid...and then i just ran power back to the compressor with a fuse between the compressor and battery...i still would like to use the auxillary switch thats inside the truck for the main power to the pump though so i can shut the pump off in case i dont want the pump turning on for whatever reason
April 5, 2009Sandman121,
I wired my air horn the same way with a pressure switch at the air compressor to the storage tank so the compressor shuts off automaticly, as well as having a switch in the cab. I don''''t have the Fancy 08 so I needed to add a switch to my dash.
March 22, 2011
the relay you need looks like this
the power coming from your aux switch needs to hook to terminal #85
terminal #86 goes to ground
Terminal #87A goes to your factory horns
Terminal #87 goes to your air horns solenoid
Terminal #30 goes to the output from your steering wheel horn switch
so when your aux switch is turned on you have air horns, and when it is off you have factory horns
hope i helped sorry so late i just looked at the date!!!!!
March 22, 2011I just cut my horn wire at the fender where it is running down to the horns.
I put a double pole double throw relay with a 12 volt coil in on the fender,
wired the horn wire from the steering wheel to the common terminal on both contact sets of the relay.
then ran the stock horn wire to one set of contacts (normally closed).
then wired the other contact set (normally open) on the relay to the air horn solenoid.
I have a toggle switch on my dash board that controls the coil to my relay I installed in the existing horn wiring system.
when I turn my switch "ON" my relay coil switches the contacts and my air horns operate from my horn button.
when I turn my switch "OFF" my relay coil shuts off, the contacts go to their normal state and my stock horns operate from my horn button.
this IS exactly what you are trying to do.
October 20, 2011I wish I had done what Lounge Lizard did it sounds better, but I put in a on/off switch for the compressor and used the cigarette lighter as a push button to blow the horns. I have a set of General train horns on my truck. The lighter wont stay pushed in just works as a push button.
October 20, 2011I could be wrong so please correct if I am. Sandman wants to use an aux switch already installed instead of a toggle. My `05 has these switches and the wires(4 of them) are coiled up by the fuse box under the dash, don`t know about the `07. I believe that my wires are white with varying colored lines to identify them to the switches.
Using Lounge Lizards method, which I like and seems simple enough and effective, couldn`t the relay be energized by the aux switch to activate the air horns and deactivate the stock horn. Then when the switch is turned off the relay would close and reactivate the stock horn.