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Horn Sounds Unintended 2015 GLA250

297 Views 2 Replies 2 Participants Last post by  Supertav
Anybody experienced horn going off by itself while driving or as soon as you turn the key on. I already replaced the horn relay to no avail. Currently I am running with no horn as I removed the horn relay to avoid pissing people off or worst get into road rage.
2015 GLA 250.
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Horn blares continuously or just a quick beep? Either way, sounds like a bad connection in-line or the button under the airbag that triggers the horn is stuck/inoperative. I’d start with the steering wheel area if the horns were replaced and you’ve ensured no damage to connectors
The horn blares continuously loud! Today I replaced the clock spring, but that expensive attempt to repair the stuck horn didn’t fix the problem. As soon as you turn the key to run position the horn goes off continuously. BTW, before this horn blaring issue started the horn button wasn’t working and still is. That made me think that it was the clockspring based on what I’ve researched online. That was a $430 mistake as I have to buy the whole steering column switch assembly that controls the transmission shifter, wiper and cruise control. Anyway. In my continued troubleshooting I noticed that something is activating the horn relay as soon as you turn the key to on position. I can hear the horn relay activating or clicking. So, I removed the horn relay and put a test light (already driving my neighbors and my wife crazy) I noticed on the relay connector/circuit there is a steady 12v feeding the horn relay. This is normal you have to have 12v source to the relay, but once you turn the key to on position another 12V comes on to one the relay leg or circuit causing the relay to activate and sends 12V to the horn and off she blows. That additional 12V feed to horn relay goes for about 1-2 minutes causing the continuous blaring of horn. What makes this problem even more complicated it’s intermittent. Half of the time you turn the ignition on horn goes off and sometimes it doesn’t. I am suspecting there’s a wire short somewhere in the horn circuit feeding that extra 12V to the horn relay as if someone is pressing the horn button. Again horn button still doesn’t work even after replacing the Clockspring. I am stumped. Any suggestions or any known horn recall or technical service bulletin that anyone can share is really appreciated.
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