Parts is not always parts!
 

Thank you, Dr. Sternschnuppe.

For LHD cars, the base of the 9-plug version is 124-540-00-69 and the cover is 124-545-00-83. So LHD and RHD cars have different bases but the same cover.

BTW, the wire color codes are:

Pin 1 red/white stripe (large-diameter wire, +12V all the time)
Pin 2 black/red stripe (large-diameter wire, switched 12V, position 2)
Pin 3 brown (large-diameter wire, ground)
Pin 4 gray/blue (illumination)
Pin 5 black/gray stripe (large-diameter wire, switched 12V, position 1 or 2)

Here's the diagram (looks like I moved it to a different sub-directory, sorry!).

Jeremy

http://i323.photobucket.com/albums/n...X30_40716a.jpg

Great write up with super pics ... thanks !

Question on N40/Instrument Illumination Control Unit on a '93 500E:

When the Ignition switch is OFF, all the lamps that N40 controls stays on indefinitely.

However, if I turn the ignition switch to position 2 (right before starter cranking), the lamps controlled by N40 goes out.

I disconnected the instrument cluster rheostat/dimmer, and the lamps controlled by N40 stayed on.

That is, what is the fail status of N40 ?

My thinking is that N40 is either receiving a signal to "power up" those lamp, OR N40 is failed (N40 lamps stay on when rheostat and instrument cluster is removed).

Thanks,
:-) neil

N40 is a transistor, or possibly a couple of them. Transistors can fail "open" or can short internally. Since I don't know the internal design of N40, I can't be sure what exactly has failed. What you are seeing is of course not normal and AFAIK, replacement of N40 is the only option.

Jeremy

Just a quick note to say that on RHD cars (mine, at least: a UK registered '93 320CE) the connector is under and to the right of the accelerator pedal. You don't have to remove the transmission tunnel carpeting etc to get to it!