Horn wiring

Earlier models had the horn relay out in front of the alternator on radiator support, near the horn(s). I don't recall what year this changed.

i found the plug with the violet and green wire under the dash for the relay, but cannot find the ground wire that's connected to the horn button at the wheel to supply the ground. I jumped the ground on the relay to a good ground and the horns worked. Need to find that black ground from the button..... found it on the plug, but that goes to the fuse block.