Hi all! I just bought a 1979 300SD, to add to the 85 300DT , and the 83 300SD I allready have. The ignition switch is not pluged in all the wires are hanging down. The car is started by touching two of the wires together. I have no idea where they go. the barrel plug has the numbers p,30,50,r,p30,30,15,15. Does anybody have the order of what wires go where. I am at a stand still untill I can get the right order. Thanks for the help!!!

I replaced a sticking ignition lock on my 82 300CD and the harness plug on the rear of the ignition unit separated during re-installation. The pins are loose and I've also been searching for a schematic that shows correct order for re-inserting the 7 pins.... arghh.

Here is a link to the W123 chassis ignition switch wiring.

123 ignition tumbler wiring
http://www.peachparts.com/shopforum/showthread.php?p=1395165




Have a great day.

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1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

I can't find my W116 chassis data at the moment.
Try the following links.

Ignition Cylinder Tumbler replacement; mixed diesel/gas
http://www.peachparts.com/shopforum/showthread.php?p=1065596

Did you ever find a wiring diagram??? I have the exact same problem and can't find a wiring diagram anywhere. I have the same PIN numbers

http://www.peachparts.com/shopforum/showthread.php?t=257585

download the pdf file which is the complete wiring diagram for your 78 ....

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)