My horn is now working.
I thought the Horn contact was broke. It was not hitting the horn contact ring on the steering wheel. I little investigation found the contact button has slipped out of the holder. I popped it back in place and the horn works now.
The horns are just in front of the front wheel area. (look behind the side markers)
I find it difficult to believe that that all the horns quit at the same time and would look for a common culprit. (Horn switch etc.)