Horn sounds continiously
 

The car is a 95 S320, I have removed the air bag, and searched on previous posts. But I don't know which part I need to replace.

Do I need to remove the steering wheel.

Jack

Answer
 

If it is the alarm system horn going honk, honk.
Use the key in a mechanical door lock to LOCK then UNLOCK, and hope it dis-arms.
FYI: This alarm module is a vehicle disabler security item and has been superseded NINE times. Note: Any replacement alarm module MUST be ordered by VIN# and coded with the MB factory tool.
The alarm module is in the passenger rear quarter panel, shaped like a large capitol "L".


If it is the standard vehicle horn on continuous blast.
#1. Disconnect the battery.
#2. Open the hood.
#3. Remove the primary fuse panel cover.
#4. Remove the Secondary fuse panel cover.
#5. Connect the battery.
#6. Remove the (ice cube size) relays one at a time until the trumpet horn goes off.

Relay
MB# 0015429919

#7. Install the Secondary and primary fuse panel cover.
#8. Replace the defective relay at your leisure.


Data for you.
Locate the pair of horns under the front bumper, and disconnect both of them.
FYI: The horns have been superseded three times each.

Horn, 405 Hertz tone
MB# 0045424120

Horn, 485 Hertz tone
MB# 0045424020



.

It fixed
 

Thanks for the post.

I replaced the soft plastic washer holding the horn ring, some of them were totally wore out from year of service.

The horn ring is under the air bag.

Jack

Wow
 

A 1995 S320, and the isolators where worn out !! :eek:

That is very strange.

Maybe the car spends a lot of time in the city....

Jim

same thing happened on my 1995 e320.... i replaced the washers as well....

I've been trying to switch steering wheels from a W140 (97) into a 92 W124 with the slip ring connector. The ground is different for the horn ring but I did managed to get the wheel installed and put the ground (brown) wire from the slip ring connector to the male pin on the bottom part of the horn ring. No problem. Tested the horn and it worked !!!!....for a couple of toots...only. Then I could hear something clicking when I tried the horn but no horn. Turns out the noise is from the horn(s) themselves. A diaphram I assume. It's trying to work but nothing. Anyway, no horn...BUT........ if I disconnect one horn (either one) then the other horn will work. So it would seem that when I press the horn there is less than 12V going to the horns.....is there a relay somewhere that maybe I blew ?