Advice on running horn switch.

Hello everyone! I've bee nreading for a while, and just registered. I stumbled on this site, and it's really great. Anyway..

I traded my 99 Eclipse GTS in on an Outlander last month ( 4 cyl), since the kids are getting bigger. Anyway, The horn is ok, but I feel from time to time, I need a bit more "punch" when someone cuts me off, if you know what I mean. I found a really nice 139db Stebel airhorn at
Twisted Throttle , and mounted it back behind the grill on the passenger side. I used a strap of 1" aluminum between the headlamp mounting bolts, with about a 1" Z-bend. It fits perfect. But here's the deal; I want a switch in the dash to select when I turn it on, so sometimes I can hit the horn, and it's normal, and other times, it'll really shake their teeth.
I just need to know where I can snake the ground wire into the cab, so it can go through the switch, and then ground.
any Ideas?

Damn, I hate people that cut me off too, but I won't replace the horn...lol. How big is this, That will surely rattle their cage a bit. As for the electrical advice, I'm sure someone will answer soon. I'd stay away from the cops with those bad boys.

Thanks for the reply. I'm putting in a switch to allow to use either just the factory horns, or by flipping a switch, the factory horns AND the air horn. That way, my alarm, and for inspections and normal stuff is stock, but when i want some "oomph", I've got it. Sorry if I wasn't very clear.

hope this helps, if you are talking about coming from the engine through the firewall, if you pull the carpet back under the driver side front, you should see a small perferated circle, peel that back and you can drill right there, thats where i drilled to run my amp power to the batter, i might be able to get you some pics later.

This is gonna sound great! Woo!
Where are you looking to put the switch? I'd suggest putting the switch where the powered mirror controls and instrument dimmer is......

Check out the link on my first post for Twisted Throttle, they have the review. It's a bike site, but loud is loud. I'll post some pics shortly.

WOW...OK COOL. PICTURES!!!