Trouble shooting Horn issue

[jbgroby]

Got a strange puzzle I'm trying to figure out. I purchased a new horn from Classic Parts (6 months ago never took out the box) and have wired everything up, horn don't work. I called Ez-Wiring and they explained you ground out the green horn wire from the fuse block and the relay should 'click', it does. So we know the fuse block relay is doing what is should.

I suspect a bad horn out the box, so I connected a set of jumper leads to the pos/neg battery post and touched the contacts on the horn - no joy.

I stopped by NAPA today and asked to test a new horn and I jumped it off a new battery, their horn did not blow either, so I'm testing these wrong? Is there another way to test a horn, I though it would blow if I jumped it off the battery directly?