Symptom Chart

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Symptom Chart

Condition	Possible Sources	Action
The horn is inoperative	Fuse Circuitry Horn Clockspring Horn switch (part of the driver air bag module) Central junction box (CJB) Powertrain control module (PCM)	Go to Pinpoint Test A .
The horn is always on	Circuitry CJB Clockspring Horn switch (part of the driver air bag module) Vehicle security module	Go to Pinpoint Test B .