Need help with air horn

[pSycHOarsOnisT]

I installed a wolo air horn on my 89 and just had it as the only horn, it got a little annoying having it Like that. I want to put it in my 02 now but want to have a switch so i can choose between stock and air horns, just wondering how i would wire this.
Thanks

 

[UrbanRedneckKid]

Research how a 5-pin relay is wired.

Attach your stock horn to terminal 87a, and your air horn to terminal 87,
Then the factory horn wire to terminal 30.
Run fused battery power to terminal 85,
Run a wire from terminal 86 into the cab, to a switch, and from the switch to a ground.

Your oem horn will sound if you press the horn, until you turn the switch on, then it will be the air horn.

 

[pSycHOarsOnisT]

Great. Thanks man, glad i kept the relay that came with the horn.