My R52 is a recent acquisition and I'm having trouble figuring out how the steering column horn is supposed to work. The center airbag module moves around too much and the horn does not work reliably when you press it. Found steps for how you access the clips and had no trouble removing the airbag module. But ... now I'm not sure where to go from here to 1) adjust whatever is needed to "tighten up" the airbag module and 2) to get the horn to work reliably.

For #1, I'm guessing maybe adjust / tighten the three star bolts (circled in picture) so the airbag module clips deeper, which should eliminate wobble?

For #2, I've noticed that the horn only sounds if I depress the left plate. I have to imagine the right plate is also supposed to sound when depressed and that would be the source of the unreliability. I can't seem to find anything about how this part is supposed to work, though. Any advice or things to check?

Cheers!
Sean




Are there adjustment specs?

 

Yes, should make contact on both/ either side, so maybe could be adjusted or cleaned? If you have a multimeter check for electrical continuity through the horn connector terminals when you press the plate

There is a little wobble "Front to back" in the fit of the airbag into the steering wheel spring clips, but no rotation on mine.

My horn was dead and ultimately it was the clock spring / slip ring (p/n 6800997) under the airbag that had failed, its a common failure mode for the horn, and could easily break intermittently I suspect. After checking the continuity on the metal work I then checked the clocksping for continuity too. I had a wiring diagram somewhere to tell which terminal connects to which on the spring, I'll see if I can find it. Do you have the multi function wheel with the radio and Cruise control buttons?

 

Thank you so much for the horn wiring diagram! That is incredibly helpful. It'll help me check for continuity on that right side.