Continued horn troubleshooting....

I'm still in the process of trying to figure out why the horn on my '91 XJ doesn't work.

Today, I accomplished the following:

1. Verified the horn itself is properly grounded through the unibody.
2. Verified the horn itself is good. Ran 12V+ directy from the battery to the only wire terminal on the horn. It just about blew my ears out....

Now, I'm confused. I had printed an article stating the horn is a switched ground circuit and should have two wires going to the horn itself, one that grounds when the button is pressed and one that is constant hot. Did the XJ horn vary from year to year? As I said, I have only 1 wire and it's wasn't hot. This one wire was mostly green with a brown stripe on it and appeared to never have been tampered with. This article also stated that the horn pad should have some sort of connector on it. Mine had nothing of the sorts.

How is this thing supposed to work? What should the back of my horn button look like? The one I have now has only a white plastic ring on it with about 6 teeth (2 of which are broken). Any advice would be greatly appreciated. Thanks.

Don´t know all the answers to your question, but may be able to get you on the right track. There is a horn relay in there someplace, don´t know the location, have never had to troubleshoot one. Horn slip ring/horn button, grounds the relay (closing it) allowing current to flow through the relay to the horns.
Most times my horns have messed up for me, it was the slip ring, that keeps a constant contact as the steering wheel is turned. I´ve installed the slip ring and spring in the wrong position (or was it the wrong order, forget) a couple of times and have had the contact (looks kind of like a electric motor brush/piston or pin) and/or the spring (behind the contact) pop out and land on the floor, usually to find it in the carpeting after I´d assembled everything. Have also had grease on the contact pin/piston and slip ring mess with a good contact on occasion. If I remeber correctly there are also some insulators to keep the screws from contacting the slip ring.
The innards for most of the Jeep steering columns (at least the upper part/non air bag) that I´ve messed with, are mostly, the same as Chevrolet. Have often used a Chevrolet blow up (drawing) and instructions for assembly/disassembly. The Chev. drawings and instructions are often easier to find at the library than Jeep, cost a quarter to make a copy.
Had a look at the Jeep (93) FSM for the air bag column, it´s not much help for horn button assembly and troubleshooting.
Hope I´ve helped a bit and not confused.