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

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
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"Oh lord won't you buy me a Mercedes Benz."
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