I have a Seville that was sitting for some time (6months) and now the horn does not work. I pulled the steering wheel apart and checked the contact, but it seems clean. I also was not able to figure out which fuse powers the horn. The ones in the trunk didn't list a horn, nor did the ones in the engine compartment.

 

Just in case anyone checking this is having a similiar problem, I did find out that the horn is run through a relay under the hood. It's in the bank of breakers that is hidden, not the nice easy ones. So once I get into them, I'll let you know if it works again. Just a note for anyone pulling their horn/air bag assembly, watch that connected wire for the horn. Not the yellow air bag connector, but the little black one. You need to turn the black plastic collar counterclockwise to get it out. If you don't, it will break the holding retainer inside the column. Mine got broken likely by the shop I had owrking on it, but I was able to cut in a new slot 180 degrees on the other side, and make a way to reconnect without replacing the whole thing.