Installing multiple horns

Hello, I sort of new to these things but I recently purchased a Hornblasters Shocker Train Horn. I also have an older aftermarket air horn. What I would like to do is pretty much what is shown in this video, I want to wire the Shocker, air horn, and stock horn to the steering wheel. My question is how would I wire something like this?

Thanks in advance for your help

It’s actually quite easy to do, so easy,it’s hard for me to explain!

Basically you have to find the wire that is coming from the steering wheel horn push button, then break into the wire and divert it to three switches.
Simply loop it into the top of each switch.
Then out of the bottom of each switch you connect back up the wire going to your stock horn to the first switch, then a wire going out the bottom of your 2nd switch to the Shockers solenoid & then a third wire out of the bottom of the third switch to the aftermarket Horns solenoid.
Then, whatever switch you have switched on will operate the horns you have selected.
You will need to work out if it is a positive feed out from the steering wheel push or a negative feed, it’s still do able either way.

Welcome to the forum!