The problem with the Haynes manual for the W123 series is that it was printed in England. You'll notice that some of the wiring diagrams are for UK models. Haynes and even Chilton manuals are general manuals. The offical MB manuals would be best of course.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section