2002 Mercury Mountaineer My horn won't stop blowing

CLABADIE

MEMBER
2002 MERCURY MOUNTAINEER

Noises problem
2002 Mercury Mountaineer V8 All Wheel Drive Automatic

At first my horn would just go off at odd times by itself. Then I notices the seat controls were triggering it. I took it to a mechanic and they disconnected the passenger side seat. I took to disconnecting the battery so it (the horn going off) wouldn't happen at odd hours at night and or kill my battery. Today I when to drop my son off to school and as soon as a connected the battery the horn went off like someone was leaning on it and wouldn't turn off even with the car turned on. I just need to know what can I do to disconnect the horn, pull out the fuse, something to make this stop so that I can use my car till I see the dealer on Sat. That when I have an appointment to get it seen.

Thank you for any help
Charlene.

1 Reply

CARADIODOC

MECHANIC
33,723 POSTS

The horn switch used to turn on a ten-dollar relay that turned on the horn. Simple circuit that worked fine for decades. Now Ford has decided there is a better way, ... For their bottom line ($). The horn switch sends a voltage to the most intelligent computer on the vehicle, the instrument cluster. The instrument cluster interprets the command and sends a digital signal to the Front Electronic Module (FEM) which interprets that signal and turns on the horn. That's right. Two very expensive, unreliable computers involved in blowing the horn. No more ten-dollar relays.

There are two horns under the hood. If you follow the noise, you should be able to find them and disconnect their plugs.

Caradiodoc