Im building my own kit with the viair 150psi 2gal air source kit and a set of dual big rig horns. heres where it kinda gets tricky…
I want to wire it with 2 switches, 1 to switch the power on and off for the compressor, and 1 that I can use to switch between stock horns and air horns so I can still use the horn button on the steering wheel but choose between stock or air horns.
Im also planning on using a viair pressure gauge and having it above the switches in the cab, but for that dont i just need to ‘T’ off the air line and give it power?
This switch will be wired into the pressure switch on the tank, since the pressure switch is what tells the compressor to turn off/on.
Switch 2:
This switch will be wired into the horn wiring and is a simple bypass; in one position it sounds the regular horn, and in the other its run to the solenoid for the air horns.
You will need a SPDT Toggle switch (3 prongs).
Cut the wire leading up to your stock horn. That gives you 2 wire leads.
Attach the wire going right to the stock horn to one of the Side prongs.
Attach the wire leading clear back to the steering wheel to the Middle prong.
Attach a wire from the remaining Side prong to your horn solenoid.
The LED is powered when you flip the switch, which is nice because it lets you know you’re using it and doesn’t require another kit to install a separate indicator.