Instrument Cluster pinout
 

I have a 1984 300SD with an oil pressure problem. It is not the sender as I replaced that, and I tested the wire to the sender with an ohm meter. Does anyone have a wiring diagram for the instrument cluster pinout on the round connector that plugs into the instrument cluster with the Oil pressure, Water temperature, and Fuel guage. Also have any of you ever replaced the oil pressure guage with an aftermarket VDO guage that will work with the stock sending unit? Thank you for your support.

Well I resoldered all the solder joints I could get to on the instrument cluster circuit board for the 2nd time and the oil pressure is working again. Hopefully for longer than the 2 months it worked the first time I resoldered everything. I also resoldered everything on the extra instrument cluster with the water temp guage that was not working. Hopefully that cluster is now working I need to test it as well. The pin out would still be helpful.

Oil pressure is on socket 15, brown/green on the wire.

Water temp. is on socket 2, green on the wire.

Fuel is on socket 3, blue/black on the wire.

Thank you Brian as usual you have been extremly helpful.

this may help, if it worked

Thank you for the wiring diagram I printed and saved it. Knowledge is power to do stuff.