I have been driving around (in my 99 sunfire gt) for about 3 weeks now with the fuse for my horn taken out. About 3 weeks ago when it was super cold i came out in the morning to my horn going off. I got in the car right away and hit the button and the honr shut off. I heard a click sound when i hit the button. I didnt think much of it (thought to cold was the culprit) and went on my way to work as i was driving wodn the road and i hit bumps the horn would start randomly going off. and when i pushed it that woud shut it off. then again randolmly ar work in the parking lot it wne t off again so I said screw it and took the fuse out. Now that the weather has gotten warmer i put the fure in and it started gain right where it left off. randomly down the road it started going off and i had to push the horn to make it turn off again. Since i am hearing the clicking that means the relay is good right? Hwat do you guys think is causing it. alsmot sounds to me like a short somehwere but idk.
I had the same problem with my 95 Buick Lesabre. The pressure switch that you push to sound the horn is failing. That switch is located in the airbag just beneath the outer layer of material (the surface you can see when you look at the steering wheel). I had to replace the ENTIRE airbag to replace the switch. Unfortunately, the sunfire has the exact same setup.
2002 Pontiac Sunfire (LN2)
I had that issue too, never figured it out. My 98 did it in really warm weather. I replaced the relay because I figured that it was screwed up, but that only worked for a week. (My car did this on a VERY regular basis)
As Karl said - it might be that contact switch, take the airbag off, clean any corrosion off (yeah, sounds weird, but it might be there) and reinstall it. If you still have no luck, hit up the yard for a new airbag. They are pretty reasonable priced. (I paid $25 for mine) and just replace it. Beyond that, check the actual connections at the horn (passenger front under the headlight) and make sure those wires aren't corroded and shorted.
As I said before, I replaced the horn itself, the airbag and the relay, and I still have issues with it every now and then... I just wired a switch in to the fuse to shut power off to my horn at night.
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This was great to find. My friend has an S10 that kept waking him up in the night when the horn would go off. He has the fuse out of it now, but maybe we can get it fixed and he can use it again.
