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!

__________________
Feelstranger
My Wheels
1991 Audi 200 20V Avant
1991 VW Westfalia Syncro/Audi I5
1983 Mercedes 300D turbo
1972 Kawasaki H1 500 Mach III
1970's Limongi/Campy road racing bike
1942 Old Town sailing canoe

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?

__________________
Feelstranger
My Wheels
1991 Audi 200 20V Avant
1991 VW Westfalia Syncro/Audi I5
1983 Mercedes 300D turbo
1972 Kawasaki H1 500 Mach III
1970's Limongi/Campy road racing bike
1942 Old Town sailing canoe

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.

__________________
Feelstranger
My Wheels
1991 Audi 200 20V Avant
1991 VW Westfalia Syncro/Audi I5
1983 Mercedes 300D turbo
1972 Kawasaki H1 500 Mach III
1970's Limongi/Campy road racing bike
1942 Old Town sailing canoe

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.

__________________
Keep us posted especially if your problem is solved
Present cars:
My car: E-class 420CDI, 2008, W211, V8, 180 000km

Wife's one: C-class 220CDI Sport Coupé, Euro, 2002, W203. 345 000km

Son's one: GLK class 220CDI, 2009, W204

Sold E class 260E, W124, 1988 beloved car sold after 489 000 kilometres of reliable services (engine M103, clutch and 5 speed manual gear box all original).

E-class, W210 320CDI, 2000[/B], 225 000km, Sold

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...

__________________
Feelstranger
My Wheels
1991 Audi 200 20V Avant
1991 VW Westfalia Syncro/Audi I5
1983 Mercedes 300D turbo
1972 Kawasaki H1 500 Mach III
1970's Limongi/Campy road racing bike
1942 Old Town sailing canoe

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.