Found this in my old saved files. Reprinted as I found it. May help.
"From: Bob DuPuy Subject: Re: [DIESEL] Swapping Euro Lights When I added euros to my W126 I scrounged a 6 hole plug from the tail lights of a W114 at the local u-pull yard. I had saved the wiring conversion instructions from a much earlier post. Here is what I have without attribution. - - old pin 2 (brown) goes into new pin socket 2 - - old pin 4 (white) goes into new pin socket 4 - - old pin3 (yellow) goes into new pin socket 5 - - old pin 1 (green) goes into new pin socket 6 3) replace back cover, plug it in, and enjoy much better lighting! "
The Golden Rule
1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)