W124 '86 300E
What has to be done to silence the seat belt/ign switch buzzer? I want to be able to turn the key w/out hearing that 5sec noise. (I'll put on the seatbelt after, I promise.)

The other day, I told an indy MB mechanic to do this for me, he mistakenly thought I meant the buzzer wouldn't stop even After I buckled up, so he bridged the driver's seat belt wires and now I've lost the option to quiet the buzzer by buckling up before starting the car -which I know I had before.

The mechanic claims the buzzer is designed to always sound when you 1st start the car, whether you've buckled up beforehand, or not (no way). And he thinks that the only way to stop the buzz would also result in loss of my interior lights and electric seat functions.

Someone please tell me he's wrong, and what must be done to gain blissful silence... I don't mind losing the buzzer warnings entirely (incl lights left on & key left in ign) if necessary, but would like to find a solution that doesn't require taking the dash apart etc etc, if possible.

I got rid of MB buzzer(annoying) and installed Olds Silhouette chime type buzzer. Sounds very soft and modern. To mod yours or to disable it completely one must remove buzzer module located behind instrument cluster then open module and using soldering iron solder out buzzer itself. It's a small black box inside module with 1/4" opening on top. After it's out you can solder wires in its place and connect any chime or buzzer or even 12v light bulb since it gives out 12v and buzzer buzzes. Then 12v is off in about 5sec. I don't know if you can get to module simply removing gauge cluster(I think you will be able thought check on that) because I did mine when I was changing evaporator so my dash was all out. Hope it helps.
Good luck
Victor

__________________
1999 ML430 Silver 135k ml
Smoked LED taillights, Alpine in-dash DVD player, 12" sub, Pioneer components, 2 amps, 4200k HIDs, ML55 headlights, 20" rims, mirror LED blinkers

SOLD. 1996 E320 145k ml. Burgundy

SOLD but miss it everyday 1992 500sel Black
Chime buzzer mod,Alpine CD/MP3 player with stock amp,Euro headlights,S600 grill,20" rims, BEST CAR EVER!

SOLD. 1990 300E White
187k ml,smoked tails,Euro headlights,17rims,Intake,12" sub in first aid kit,alarm/autostart,buzzer mod

Thanks Victor, and congratulations of ridding yourself of the single biggest annoyance designed into the car, you lucky dog! But from what I've read of a few who've tried to get at the buzzer unit itself, it requires more labor than I'm willing to put in or pay for.

What about a simple solution, like a well-placed wire snip? I've seen a post from at least one person who said they figured that one out w/out losing their interior lights.

The W124 buzzer module is indeed located behind the instrument cluster, so it's a good opportunity to fix the burned out lamps and faulty gauges that you've been putting off doing (that's another story).

Removal of the module is a true PITA. The module is attached to a bracket with a screw that you can't reach. The bracket holds two modules and a ground distribution thing. The buzzer module is on the left -- it has an eight-pin plug. There is a screw in one location and a nut way in the back (firewall) that attaches the bracket. Both must be removed. Put something sticky (glue or heavy grease) to keep the nut attached to your socket. A magnetic socket will also work -- the nut is ferrous.

I removed the plugs from the two modules after removing the screw and the nut but it might be easier to unplug first. Be careful not to pull out the two vacuum lines that go to the ignition switch -- that is your 'engine stop" function.

Once the cables are unplugged and moved to the right side, carefully wiggle the bracket loose and pull it out of the cluster opening. The ground wires can remain attached. Now you can remove the one screw that holds the buzzer module to the bracket and repair or replace it. The part number on mine is 004 545 07 32.

When replacing, again be careful to not disturb the vacuum lines and don't drop the nut that holds the back of the bracket to the firewall.

To remove the module from its case, clamp the bracket in a vise and use four small screwdrivers to spread the case. Carefully pull on the connector pins with a needle-nose pliers or two and the module will pull out, scattering screwdrivers everywhere. You can then get at the insides.

Has anyone had success repairing this sucker? The device (see pictures) is all discrete -- no ICs -- so it can be tested and parts replaced. There are three transistors, a mess of diodes, and three electrolytic capacitors. The latter are always suspect. In addition, it looks like the "resolder everything" technique that has worked on cruise control modules might work here.

Given the relatively low cost of the module (at least in Mercedes terms) and the difficulty of access, it might just be best to replace the thing with a new one. I haven't decided yet.

Jeremy

Attached Thumbnails

   

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I ended up buying a new module.
Then I discovered that the front dome light had some fried components so I got a good used one.
Now everything works except two of the puddle lights.
I'll have to take those two door panels off to see what the problem is.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Jeremy,

I swear, I think we are on the same wave length in terms of maintenance and mods...but I'm about a 1 yr behind you

Thanks for your excellent advice. I took some more pics to help people out in this thread.

Pic description:

Pic 1: the location of the relay is behind the instrument cluster. once removed, the bracket and the two housings are located on the right side. the buzzer housing is attached to the left side of the bracket. theres another housing attached on the right of the bracket. dont know and didnt research what it is.

Pic 2: use a 8mm ratcheting wrench to remove the left most bolt. there's a 10mm nut (sorry, pic says bolt but its a nut) way in the back that needs to be removed too. you will need some long extensions

Pic 3: here is a pic of what you remove

Pic 4: here's a pic of the bracket and housings turned upside down

Pic 5: for you curiousity seekers, here is the buzzer opened. i cut it with a fine dremel disc

Attached Thumbnails

       

So what I did was I cut the metal device up on top and snipped one of the connections inside the box. Result = no noise. I took a 2 part epoxy glue and glued the lid back on top

Later, I may find a suitable, more pleasant door chime like from another vehicle. But for now, NO annoying buzzer. Woot!

Pic 5a: Buzzer case opened

Pic 5b: Buzzer metal thing cut down

Pic 6: After I cut it down, I put the housing back on and put a sticker labeled "buzzer" so I dont forget in the future when I put on a new door buzzer chime

Attached Thumbnails

     

Good job, Bob.

I am concerned about removing the buzzer completely since it has other functions like "key left in ignition" and "lights left on." Since you can't lock the car without the key, #1 is not as big a problem as #2, which I have been known to do. Hard to start the car without the battery.

In my '85 300D (W123 chassis), I was able to silence the buzzer for "seatbelt warning" by unplugging a connector under the driver's seat. It still works for the other functions. Maybe that could be done in the W124 cars also. Has anyone looked under the seat? I confess I have not done that, surprising since the buzzer is so annoying.

I used to have an Oldsmobile and can confirm the nice chime that Victor installed as a replacement for the buzzer. That looks like a good project for some day when I've forgotten how miserable a job it was to get the buzzer out.

Jeremy ("take the reds, man . . .")

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

take the reds! take the reds! Miss those guys. Nancy Reagan, eat your heart out!

Yes, I've been known to leave the lights on, but to me for the time being, its a small price to pay for the golden silence of not being forced to listen to the buzzer during the glow plug warming stage.

some of my off roading friends have squirted silicon sealant in their buzzer housings to effectively muffle the buzzer sound. works for them, but ive heard it, and it sounds worse than just leaving well enough alone! as you can see here in this pic i took of my 99 4runner, the toyota buzzer is easily accessed when you pull out the instrument cluster:



I'm looking for a suitable buzzer. I trolled around this site for recommendations and a person here named wjm suggested and installed a Mallory Sonalert sc616cp but then a sc616cpn b/c it was louder:

Thread here: http://www.peachparts.com/shopforum/showthread.php?t=69271

Regarding alarms and chimes, thomaspin's name and website keep coming up quite a bit. might need to investigate... http://www.pindelski.com/

i just wanted to update this thread:

other than not having the warning buzzer alert you for open doors and lights, there are no other ill effects of disabling the noise making buzzer. personally, i am enjoying this and can live w/o the buzzer for open doors and lights. i always hated the screeching buzzer when turning on the key. my ears are loving the silence

sorry for reopening this old thread and sorry if what i am about to say has been said before. On my 94 E320, I get in my car, I hold the seatbelt release button down for a few seconds with my left hand and then at the same time turn the key to start the car. This way no buzzer for me!

__________________
1994 E320, 145,000 miles

There is also a two pin connection under the seat that, when disconnected, disables the buzzer for seatbelt startup only. That way you still won't end up leaving your lights on because you're used to the buzzer! I believe the wire colors are green and brown.