Hi all, I need some help with my 87 300SDL. I changed the diff out to the 2.47 LSD. Did you know the gas axles are not the same as the diesel axles? I didn't--but they aren't. Anywho, that's not my problem. I was installing the Dakota Digital SGI-5 to correct the speedometer error (speedo was reading slow, of course). There is a 8-hole rectangular plug on the back of the instrument cluster. When I pulled the plug, the cap came off, and the wires came out of the plug. I didn't get the order of them until it looked like an octopus all over the place.

This is a rectangular plug, not the big round one.

The plug seems to run the turn signals, speedo, oil pressure, some warning buzzer, the oil pressure gauge.

I found a diagram from a non-sdl w126, but it wasn't correct. My plug has 8 sockets. There are 7 wires inside. There are 6 pins on the back of the cluster. There is a faint buzzing sound now that wasn't there before. It is not the same buzzer as the "lights-on" or "key in ignition" buzzer. It buzzes when the ignition is on, whether the plug is plugged in or not. It goes off when I turn the turn signals on.

Can anyone provide me with the diagram or correct color order for these pins? I can post a pic of mine if needed.

Thanks in advance!

Adam

How about a wiring diagram? Does anyone have the ETM for this car? A pdf would be super! Thanks, Adam