location of door chime module in W126

1990 300SE. Dealer diagnosed door chime module as reason that driver's door won't activate interior light (driver's door switch OK; all other doors activate lights OK) and that chime doesn't work if key is in ignition slot. I have the replacement module but would like to know where it is and best way to gain access for replacement before beginning to fish around under the dash (already checked archives). Thanks in advance for your help. Regards, Will

[sixto]

If it's the same thing as the seat belt buzzer, it's just above the brake pedal. The big box is the cruise control amplifier, the small box is the seat belt buzzer.

Sixto
91 300SE
87 300SDL
83 300SD

[sixto]

Look for any post by member Thomaspin. There's a link in his sig line to his webiste. Navigate through cars -> technical -> transmission -> cruise control. It'll show you how to get to the buzzer.

Sixto
91 300SE
87 300SDL
83 300SD

[Thomaspin]

....the common bracket to which both the cruise amp and the buzzer (the smaller of the two aluminum boxes) are attached first - one (hidden) 10mm bolt.

Then, if my experience is anything to go by, you will need an impact hammer to loosen the Phillips screws which retain the buzzer to the bracket.

[fredsegal]

At the time you open your drivers door but before you put the key in the ignition....will the drivers power seat operate? If not there may be another reason for your problem.
The details are sketchy but it usually has something to do with that light under the door shorting out and causing damage to a (relay) located behind the passenger side air bag (or in that general area)
Somebody else here must have the scoop on this

No, the driver's seat will NOT operate unless the key is in the ignition, so it sounds like you may have hit upon something! BTW, the 'door chime relay' that I got is an 8pin relay, about 30mmx 30mm x 40mm; unfortunately I am not at home right now and cannot tell you the p/n. If anyone has info on what this other relay is I would really appreciate hearing about it, as I have am visiting my parents only until Saturday morning and only have tomorrow to try to sort out this problem. Also, is the "shorted light" on the bottom of the driver's door to light near your feet when you open the door? Thanks for the info to date, I will make up a couple of those pullers and pop out the IP to see if the relay I have is the seat buzzer or if perhaps the one I have is the one behind the glovebox (don't think the 1990 model had a passenger side airbag). Regards, Will

[Thomaspin]

....does have a passenger side air bag, so be careful. Yours may and you may want to disconnect it before proceeding.

[MB STARS]

Check the Diode in your fuse box looks like a plug with two pins part number is 000-540-42-81 $8.00, you open your fuse box it should be right at the top of fuse box right next to relays

I take it you mean the fuse box in the engine compartment at the firewall on the driver's side? Please excuse my ignorance, but only getting home twice a year I don't spend much time with this car. If there is more than one fuse box please point me in the right direction.

For information, the replacement relay I have is: 89 5120 0000

Is there anything further on the shorted door light idea?

WRT the airbag: thanks for the heads-up (guess MB was ahead of BMW on passenger safety when my 535 was made). I was planning on disconnecting the battery before embarking on this project. Thanks, Will

1. Found diode 000 540 24 81 (also has number 09 8659 24 on it). Diode appears to have no conductivity in either direction

2. Checked light on bottom of door; it was broken, and the hot lead and the ground were certainly able to short together

I'll replace the diode (assuming dealer has part). Can I do a quick check with a solid wire if they don't have part? Not sure when they try to stop backflow of current.

Next, if replacing diode doesn't fix it, is there a possibility that the relay referred to in another post is blown? Anyone know the relay part number so I can know I've found the right one?

Thanks in advance for all the help. Will

[MB STARS]

Go to Radio Shack you may find what you need (Diode) I don't have Radio Shack part number......fix your short first replace the Diode it should fix your problem. holp this help

[Thomaspin]

WillD - one word of caution. I'm not expert on air bag systems, but believe there can be stored energy retained in capacitors even when you have disconnected the battery, meaning it can still be accidentally triggered.

The way to be safe is to disconnect the air bag at the red plug (if memory serves) under the passenger front seat floor board (easily accessed under the carpet), after first disconnecting the battery.

dealer had to order part, headed to radio shack right now to see if they'll have one, thanks to all for your help.

will

Success to report thanks to those on the board that offered advice. I removed the shorted door light and then checked the diode (actually 750 ohm resistor) and it was OK. I replaced the dor chime relay, which as advised was on a bracket attached to the brake pedal frame. I found it easier to access from the bottom, but while I had the dash out I checked all of the connections. Now lots of things that didn't work before do: interior light via driver's door, seat before key is in ignition, diagnostic display and buzzer when key is turned on, and the blinking seatbelt sign above the interior light. Thanks again, now I can hop on the plane tomorrow with piece of mind that the car is a-o-k.