Dead Horn?
 

I was out driving last weekend and honked at another M3, or at least I thought I did. Loud music, car noises, etc. I figured they drowned out the sound. Then this morning I pulled into the parking lot at work and honk at a co-worker and I get an abbreviated honk and then nothing. I hit the horn a few morn times, nothing. So I check fuses 5 and 55, they're good. I try the horn again and it honks but cuts out again. Then nothing, again. Any ideas?

Ok, so it's not completely gone this evening I was driving around and tried it and it sounded like someone was stabbing a lamb. It was a pathetic wailing of a horn. Either way, it's not very safe so, any ideas?

Do you still have all steering wheel functions? My horn with all steering wheel functions and light went out when my clock spring went bad.

Yes, steering wheel functions are still there. On occasion when I turn the volume down the track/station forward button activates, but it's been like that since I've owned the car.

If the clock spring is good then that leaves the horn relay and the horn itself. Try swapping the horn relay with one of the other relays as a test. Here is a map of the relays located behind the glove box www.bmwgm5.com/E46_relays.htm.

How do I determine if the clock spring is functional? Or is it safe to assume that if I still have my steering wheel functions that it is good?

If the other steering wheel buttons are good then the horn is probably good, but, not a 100% sure thing. Taking the assembly apart to check is not easy and you risk damaging the flex cable. Try putting your hand on the horn relay while tapping the horn button. Make sure the relay clicks or just swap it with the A/C relay. Use the web page I posted earlier to determine which relay is the horn and A/C.

Ok, I finally got around to doing this. The horn relay clicks when I press the horn button. So now what? Is it the clock spring? I really do not feel like disassembling the steering wheel.

Before you tear into the steering wheel, check the connections at the horn its self.

Will do. You would think if I press the horn in the steering wheel and the relay in the glove box clicks and everything in the steering wheel is working. But, I don't engineer anything for a living so.... Thanks.

I'm right there with ya, I would look from the relay on.