What's the symptom? Very few horn problems on Fords are caused by the horns themselves. The insane engineers have involved two unreliable computers in blowing the horn. Instead of a simple switch and relay that worked fine for most of a hundred years, the switch now sends a voltage to the most intelligent computer on the car, the instrument cluster, which interprets that, then sends a signal to the Front Electronic Module, (FEM), which turns on the relay to blow the horn. Special diagnostic equipment is needed to diagnose the system, and the typical repair bill is around $800.00.
It is very rare for two horns, (high note and low note), to fail at the same time. If one of them shorts it will cause a fuse to blow. If you find a blown fuse that would be wonderful news. If the horn fuse is not blown, you might consider removing the cover from the relay, reinstalling it that way, then squeezing the contact to make the horns blow. That will prove they are okay, and you can follow the sound to find them under the hood.
One other potential cause of a dead horn is a defective clock spring under the steering wheel. That is a wound up ribbon cable in a plastic housing. If the cable is coming apart, eventually the cruise control will stop working and the air bag warning light will turn on. That will be a lot less expensive to repair than replacing a computer.
Saturday, April 2nd, 2011 AT 5:02 AM