PeachParts Mercedes-Benz Forum - View Single Post - ignition buzzer and dome light relay location

Jeremy5848 · #2 01-29-2009, 01:47 AM

I just took the warning relay (buzzer built in) off a 1992 300E 4-Matic. It was definitely located behind the instrument cluster, on a bracket that also holds a relay for the lighted switches in the console. (This latter relay allows the dimmer rheostat to handle all of the lights without overloading.)

In the attached photo, the dash light relay and the warning relay are shown side by side in my 1987 300D Turbo (sorry to pollute your forum with my diesel

). AFAIK, all 124s are built this way. The thing on top with the green wires is a distribution block for the engine speed (tachometer) signal. It is used for various things that need to know RPMs, like EGR and such.

To remove the bracket holding the two relays, you need to remove the bolt shown with the arrow as well as another bolt, hard to see, all the way back at the firewall. An 8mm or 10mm socket (sorry, forget which) on a long extension works. Put something sticky on the socket so you won't drop the rear screw into the depths – I did.

Once the two screws are out, you can move the bracket enough to unplug the cables from the two relays and then disconnect the green wire distributor and pull the bracket with the relays out. Once out, you can individually remove the relays from the bracket. They are held on with one screw each but buried at the back of the cluster opening where you can't get at them. It's a real PITA, unfortunately.

If all you want to do is to test the relay by substituting a known good one (mine was bad when I got my '87) you may be able to unplug the warning relay's cable without unscrewing the bracket (it's the one on the LEFT according to the factory electrical manual). Mercedes refers to it as "Warning Module N2/4 – seat belt, keys, lamps." Plug the cable into the new relay and see if it works.

BTW, if your warning relay is bad, I have one for sale ($10, free shipping in USA). See my post in the "Parts for Sale" section. Part #004 545 07 32.

Jeremy