Have just purchased a well-maintained 99 528i. Everything works well with one exception: the horn sound is barely audible -- sounds so wimpy it could be coming from a pedal car. Any suggestions, please?
Check the contacts for corrosion Should be near the front bumper. Your 528i is equipped with TWO horns: a high pitch and a low pitch, both in the same location. Try unplugging them one at a time to determine which one is having the problem. You might be able to remove one or both of them, using sandpaper, try to sand off the corrosion on the contacts, then try it. This is an external part and is exposed to outside air. Despite the best of care for the rest of the car, corrosion can affect parts on the exterior of the car that are not protected. If that's not causing the problem, consult this link for more information on this issue http://www.bimmerboard.com/forums/posts/704992
The other thing that it could be is that the horns are simply quieter than what you are used to hearing. Others have made this comment before and the E38 has louder horns that will plug in easily. Going further, you could replace the horns with Hella Supertone horns. They're 110 db. I've wanted to try a set myself on my daily driver...
Do you know how loud 110 db is? 110 db is loud enough to damage someone's hearing. That's about the same volume level as the noise from a jumbo jet or a rock concert. It could also cause someone to get a costly fine if they operate the horn in a locality where that would exceed local noise limits -- even if it was unintentional, such as the car's security system tripping a false alarm. Unlike a radio, most horns have no volume control, but I can't imagine the need for a horn to be so excessively loud, except solely as a theft deterrent (yeah I wouldn't mind a car thief losing his hearing as a consequence of attempting to break into or steal my automobile), which would severely limit its practicality otherwise. It's best to check local laws before purchasing an item like that. Just my $.02 Cheers!
110dB is about the normal output for an automobile horn. It is not excessive at all and won't cause anyone to be fined for the volume alone. Further, the NIOSH safe exposure limit for 110dB sounds is 1/2 hour per day. A short blast from a car horn is not going to damage anyone's hearing unless they stick their ear up to the grille in front of the horn. Also 110 dB is nowhere near the SPL of a jumbo jet, which can easily reach 140 dB at 100 yards. Auto horn systems (incl. BMW) often use two klaxons tuned to different notes, creating a chord with a missing fundamental. The resulting beat frequency is much more noticeable than a pure tone even though the overall SPL is not much increased by the second horn. If one of the two horns is inoperative, the remaining one will sound extremely weak and "wimpy" because the attention-getting beat frequency is no longer present.
I stand corrected. Thank you, Notthestig. Appreciate the information. I kind of figured that, which is why I recommended he check the electrical contacts after I consulted Realoem and determined the actual horns were positioned in an external location around the front bumper. Corrosion could be creating electrical resistance limiting the amount of electrical power reaching one or both horns.
