We have a 2004 Chevy Malibu, a generally easy to read vehicle, and today it definitely crossed over into the realm of mysterious automobiles. Potentially posessed automobiles.
My family and I went out (in our other car) for maybe half an hour, and upon our return, neighbors had gathered around to see what the heck was going on in our driveway. Our car, which has no security features or past mysterious behavior (at least none that we know of), was sitting there, completely off and unoccupied and locked, honking. Who knows how long it honked--up to half an hour?? My husband unhooked the battery and it stopped.
The question is, why on earth would a car just start honking? A fuse problem? Demons?? Previously undisclosed car angst?? And will it start honking spontaneously again? What's the best way to deal with a horn that has a mind of its own?
Does the car have a security system with a shock detector?
If it does, someone could have nudged the car and set the horn/alarm honking.
Another possibility is that the relay for the horn is a “shared” component with something else. On my '71 Charger, the relay for the horn was shared with the door open warning chime. I found this out the hard way when I left the door open for an extended period of time, the relay overheated, and the horn began sounding a continuous blast. After this happened a couple of times, I removed the contacts for the door open warning chime from that relay and never again had a problem with the horn sounding continuously.
The contact ring in the steering wheel could be touching which could be caused by bending of the ring from use and the steering wheel heating up causing the ring to expand and make contact with its counterpart in there. Its also possible that the airbag is pushing against the ring as well and causing this problem as the steering wheel heats up. Your husband should be able to remove the fuse/relay for the horn until he gets it to a mechanic or dealership because it is best to let an experienced mechanic work with the airbag in the steering wheel.
Ah, very interesting… no security system on this one, but now I’m wondering about whether the door was all the way closed or not… and it’s hot today, so maybe something in the steering wheel did heat up. Thank you for the ideas!
Another possibility is the clock spring, located underneath the airbag.
These clock springs do sometimes go bad after a few years.
Have you previously had any problems with steering wheel-mounted accessories such as Cruise Control or audio controls, or have you heard a clicking sound while turning the wheel? Any of these symptoms can be an indicator of a bad clock spring.
Since the clock spring is located under the airbag, this repair is not for someone unschooled in airbag-related repairs.
The problem is with the multifunction switch in the steering column. This switch also includes the horn contacts. This switch can be replaced by seperating the top steering column cover by removing the three torx screws located at the bottom cover. Once the top cover is removed, remove the single torx screw holding the multifuncion switch to the steering column. Unplug the electrical connectors from the back of the switch and remove the switch. Install the new switch.WARNING: PUSH THE HORN BUTTON IN ON THE NEW SWITCH WHILE IT'S INSTALLED OR DAMAGE TO THE NEW MULTIFUNCTION SWITCH AND THE HORN CONTACT RING WILL OCCUR.
Before you attempt to replace this switch, remove the air bag fuse located in the fuse box on the drivers side of the dash.