2003 Ranger XLT installing air horns

[buddyspa]

I have spent the last three days installing an electric compressor-powered air horn system and am having trouble getting them to work using the Ford horn button. It seems the horn ring is positive ground activated. I have the air horns powered through a standard horn relay and have sourced power from the battery directly and grounded the compressor to the frame. I get either a constant operation or nothing at all when I try to connect the stock horn switch to the air horns using a two position selector switch with a center off position. Any suggestions?