Instrument cluster ground? 300D
 

Can someone tell me where the instrument cluster gets its ground? I found that If I manually ground the metal back of the cluster, my electrical problems with the fuel, temp, and other lights are resolved. But I don't see where the cluster is grounded from the wire diagram.
Thanks!

PS. anyone else ever make the mistake of opening the 14 pin plug? DOH!

Ground For Instrument Cluster
 

1984 300d Turbo
Ground Is Behind Center Of Instrument Cluster Per Mercedes
Electrical Troubleshooting Manual May Be Loose Wire

Sorry, I was not clear. where is the connection on the instrument cluster? Is it one of the 14 in the 14 pin connector?

On my '81 300TD, I pulled the instrument cluster and resoldered the main ground connection paths on the circuit board on the back. The solder joint was "cold" and the solder needed to be re-flowed to reliably be a good conducter. John in ID

Yes, one of the wires in the round connector is the ground (brown wire). It goes to a ground point under the dash with several other brown wires. I would check that ground connection first.

Perfect. Thanks all. I dig in further tonight.

hello feelstranger, what kind of problems do you have with your fuel pump and the loose grounding wire ? It may help understanding and solving stalling problem on my car! thanks in advance for reply.

No problems with the pump, just the gauge - it pegged full all the time, as did the temp gauge. Additionally, the glow plug indicator light was dim.

The problem turned out to be a clearly burned out section of the ground track on the circut board on the back of the fuel/temp gauge cluster. A little wire and solder and all is well. Only thing is I don't know what caused this melt down...

I did that once, it took a wiring diagram, two attempts, and about an hour to get it back together correctly. I believe I also said "DOH!" (or something similar) when all those wires fell out.:cool: