Hi, my horns have stopped working and I need help. I can get them to honk when I apply voltage to the terminal 30 where the horn relay goes into in the under hood fuse box. So I am assuming the problem is somewhere from the steering wheel to the fuse box, I have proceeded to take out the dirver side airbag (yes I disc battery and was very careful) but now am confused as to how to proceed with the diagnosis! is there a switch inside the airbag itself? could my clock spring be bad?
I was told at the junkyard there isnt a switch inside the airbag, but am having trouble figuring out where are the contacts for the horn than, since I've opened it up I dont see anything under the airbag that the airbag presses on to set off the horn? am I missing something.
The airbag module is held in place by the fingers of the horn switch. When you press the horn/airbag, you're simply moving the airbag and the fingers all at the same time. The fingers are hooked up to a switch. The clockspring is merely a means of getting electrical connections to the steering wheel without using a contactor ring like in days gone by. Your steering wheel controls all go through the clockspring's wiring, including the signal from the BCM to inflate the airbag. (Two-way signals.)
A quick way to test it without having to disassemble everything is to remove the horn relay and swap in another with the same number of terminals (4), then press the horn button. If it honks, Voila!, it's the relay. If not, check the fuse on both sides. If it's blown it'll be hot on one side and dead on the other. If you replace the fuse and test the horn and it blows again, you have a short to ground or overload situation that needs to be corrected first.
If none of the above remedy your situation you'll need to dig some more, which means you'll need to disassemble more than you already have. You'll also need a wiring diagram for your car so you'll know what wire should be doing what. Look for the signal wire from the column to see if it sends a + or - signal to honk the horn (usually (-) but who knows engineers these days?) and then see if you can tap into it and provide the correct signal manually. If it works then the switch is suspect, or possibly the connection at the clockspring. If it still doesn't then maybe some rodents have chewed some wires and you're just now finding out.
Keep us posted on what you find and ask more questions if you need more help.
'11 LTZ, born Aug 2010, Fairfax, KS
V6/A6, Red Jewel Tintcoat / Cocoa-Cashmere, Sunroof
Cool Mods: Drop-in K&N air filter; 20% tint, DRLs on turn signals,
Painted grilles, 1-wipe washer, WeatherTech mats, CHMSL Pulser
Thanks alot for your response, I was able to figure it out with your description of the horn fingers and where the horn switches are. There is a round plastic piece in the middle of the horn switch where the bolt goes through that holds the airbag in place, and there is a metalic layer thats on this piece which had worn away on both sides therefore when I pressed the airbag it wasnt doing its job (which I think is to ground the switch...) a trip to the junk yard and 4bucks later I have horns again.... and no they are not on my head. haha
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