Air horn wiring schematic

[Turgin]

I got an air horn kit for Christmas and am working out all the details for wiring it up. I do not have upfitters and will be using illuminated toggle or rocker switches. I want one switch to enable/disable the compressor but only when the key is on. I want another switch to toggle between stock horn or air horn when the steering wheel horn button is pressed. I may also add another momentary switch to blast the air horn regardless of the position of the previous switch. Pretty standard stuff.

I've been doing quite a bit of research on the forums and think I have it all worked out but wanted some opinions on the schematic I've come up with. I plan to use the purple blunt cut ACC wire under the dash to power the switches used to actuate the relays. Constant 12V will be a fused 4 AWG wire from the battery. This is overkill I know but I also want to power an inverter and maybe some other accessories.

Hopefully I can find the stock horn wire inside the cab. From my research I understand the stocker has constant 12V with a ground trigger that is yellow w/ red tracer. If I can't get it inside then I'll put the relay out at the horn and use the pass-thru wires.

I welcome all comments and suggestions. Thanks in advance.

[mts678]

Man it's best to get upfitters! Installed in 15-30 minutes. I have my horn trigger on upfitter 1, and compressor on/ off on upfitter 2. Works great, upfitters are only hot on accessory and running.


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[Snake]

I just took a quick look, but it appears you're on the right track. Another option would be to put the on/off switch on the pressure switch instead of the compressor.

[Turgin]

I just don't have the funds for upfitters right now. I know its easy and all, but I just can't swing it right now. I intend to drill holes and place my switches inside the coin tray so I can easily install upfitters one day and not have extra holes anywhere.

[mts678]

Originally Posted by Snake

I just took a quick look, but it appears you're on the right track. Another option would be to put the on/off switch on the pressure switch instead of the compressor.

Oh it has a pressure switch, but with it also having an on/ off switch- you can turn it off and on when you want, especially when the pressure switch fails which it will eventually. And if you don't want the compressor running all the time.


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[mts678]

Originally Posted by Turgin

I just don't have the funds for upfitters right now. I know its easy and all, but I just can't swing it right now. I intend to drill holes and place my switches inside the coin tray so I can easily install upfitters one day and not have extra holes anywhere.

That will nice and clean.


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[Turgin]

Originally Posted by Snake

I just took a quick look, but it appears you're on the right track. Another option would be to put the on/off switch on the pressure switch instead of the compressor.

Thanks for looking. I thought it would be better to switch the power to the compressor just to be certain the compressor can't run with the key off no matter what.

My main concern is the polarity through the whole thing and especially the relays.

[Snake]

If the pressure switch doesn't have power, neither will the compressor.

Thinking back, I believe I wired mine that way because I could use an upfitter to power the switch but not the compressor. I was able to eliminate a relay in the process. You're obviously in a different situation (no upfitters for the time being).