If your car used to be a Police Car, it is likely the horns were disconnected and/or removed. The horns on most emergency vehicles are wired into the siren. When the horn button is pressed, the siren stops and you hear a loud electronic horn. When the horn is released, the siren starts back automatically. My 97 Interceptor has the same problem. If I can fix mine, I'll post repair instructions here.
I fixed mine on an '03 Interceptor... I wired a relay that sends hot to the factory horns (which were still there, just cut). If you remove the panel under the dash you can find the wires that control the horn. Using your multimeter, see which one gives a ground when the horn is pressed, then connect that to your relay.
I have a 90 crown vic. Send me a email address. Mine is irishone_oneirish@yahoo.com
The most common horn problems are either a blown fuse or a bad horn relay. Both should be located under the hood in the fuse box.
the fuse amp for a lighter is a 20amp.it controls the lighter,horn & cruise control
The horn relay for a "96 Crown Victoria (police model) is located on the right fender where the fuse/relay box is.....3rd relay in from the right. If you are on the right side of the car.....3rd one towards the engine.
I believe the horn is mounted below the battery tray
behind the front bumper
Most likely a short in the wire contact at the steering wheel. Look there.
on the steering wheel
Front drivers side. Mounted on the metal bumper, behind the bumper cover, towards the right front tire. Look under the front end, look up and you'll see it.
Which fuse box are you looking for the drivers console or the under hood? I can't find where the fuse box is located because my horn doesn't work and the left side console of steering wheel work
In a 1997 Mercury Mountaineer : In the Power Distribution Box ( which is " live " ) located in the drivers side of the engine compartment ( relay # 2 is the horn relay )
The horn for the 1997 Ford Escort Lx is located underneath the front end of the car. You'll have to crawl under the car face up or if you can lift the car up to see the horn. (It looks kind of like a snail shell or that kind of basic shape.)