There are two simple answers 1. the wire has come loose from the horn located near the radiator. 2. the wire has come loose from the horn button on the steering wheel. If these are not the cause than there is likely a broken or corroded wire. The grand wagoneer is notorious for corrosion and i am guessing the wagoneer is the same. good luck.
On the steering wheel
I though this would be easy since my horn still works-- so I opened my 89 Wagoneer's hood and looked and looked-- and looked some more, but never found the horn either. I DID find the horn relay (I think) behind the head light assembly on the drivers side. If you find your horn and have a minute or two please let me know at tjuul02@yahoo.com I did however recently order a new CHILTON repair manual from Rockauto.com so maybe in a few days I'll know much more than I do now about many things on this Wagoneer.
The horn relay on my 86 was taped to the wiring harness on top of the fuse panel.
On a jeep that new i would check the fuse panel and repace the fuse for the horn. The horn shouldn't be defective but if the fuse doesn't solve the problem, have dealer replace horn under warranty.
To fix a Jeep Wrangler horn, first check the fuse related to the horn in the fuse box; replace it if it’s blown. Next, inspect the horn relay and wiring for any damage or loose connections. If the horn still isn’t working, test the horn itself by connecting it directly to a power source. If it doesn’t sound, you may need to replace the horn.
check the horn fuse
The fuse for the horn on a 2008 Jeep Compass is located in the fuse box under the dashboard on the driver's side. You can find it by removing the cover of the fuse box and looking for the specific fuse labeled for the horn, which is typically a 15-amp fuse. If the horn isn't working, checking this fuse for continuity is a good first step in troubleshooting.
The wiring to the horn is shorting out at times. Check the horn relay, and the wiring to find where the system shorts when the Jeep brakes.
could be horn relay in underhood fuse box. or bad horn..
Most likely a blown fuse. Otherwise bad wiring going to the horn or a bad horn.
Yes. Remove the existing horn or horns, attach your new horn and connect the horn wires. The horn wires will probably have a JEEP wire plug on the end that will need to be removed or altered.
So what is the question about your 1991 Wrangler horn?