Horn Common FAQ, Issues and Fixes

[kimokk]

Sorry to bring up this old thread but it's better that starting a new one.

I just bought a 92 535i last week and the horn does not work. I have visited this writeup lots of times, going thru every step posted in this thread, troubleshooting every possible angle possible for a few days now. Here's what I have done:

*Tested ground from the door hinge to the carbon pin, horn works. That eliminates the possibility of a bad fuse and relay.

*There is continuity from the door hinge when grounded to the steering wheel, horn works as well.

*Cleaned ALL contacts and points of contacts including ground terminals, carbon pin and back of the slip ring.

*Bought a slip ring from PnP today, along with a steering wheel as well ($38 for both) -- slapped it on, plugged in the airbag and placed the airbag in with the torx screws in the back halfway in. Pressed the contact points in front of the airbag and it WORKED! However, after I tightened the torx screws all the way in, it stopped working again!!!

Tried to troubleshoot again, could not reproduce it. Kinda gave up for today.

Any thoughts?

Did you get this fixed? I have the same symptoms.

What is the next step?

[kimokk]

Bump

[sonic attack]

Old thread I know, this is the one most likely that come up with a google search though..

FWIW: There's an earth lead/wire that connects both steering shafts in the footwell - Only visible when you turn the wheel/shaft 180 degrees... ie: when your steering is at center the wire/lead is up top inside the dash. Mine had just worked loose and disconnected.
Nice easy fix that one...

[shogun]

Just today I got this message from Frank87 :
For those of you interested. I solved the problem. There is a ground wire between the 2 steering shafts that are connected with a flex disc. Its a simple ground wire that runs across this flex disc connection. This wire was broken and by steering with the wheel, grounded on other metal parts at some point. Hence the half working horn. Ground wire renewed and all is ok now. Here's the spot without a cable.
http://img.photobucket.com/albums/v4...pstkosp7ue.jpg
Here an improvised cable. Have already fitted a better one. http://img.photobucket.com/albums/v4...psu6gdgmzt.jpg

[honda.lioness]

The picture of the contact points and ground wire were key to my successful repair of the horn on an e30 325i today. Thank you!