Adding air horns

[btomcik]

I have a 2004 Dakota with the 4.7L V8. I bought one of those air horn kits with the two plastic trumpets. The instructions say to attach the new horn compressor to the existing horn relay on the truck. I have no idea how to do this or where the existing relay is. Any help would be appreciated.

Also, this website is a hell of a lot better than that other one www.dodgedakotas.com.