Euro Cluster Fault

[HDHD]

Afternoon all, hoping somebody has the answer to my seemingly endless problem.

I have the token fault in the cluster on my 94' 318i Touring (UK).
The fuel gauge and speedo are completely dead, I mean six foot under. No flickering or attempt to work and it's been like this since I bought her. Ive never seen them move a millimetre even with the miracle "punch"
The temperature, rpm and economy guages all work fine, even the odometer works still.

Now I have tried nearly everything I can find online to fix it including:
New ground nuts and re-soldered ground point.
Brand new batteries soldered into SI board. (Both working)
All solder joints checked everywhere and re-soldered on the SI board and the cluster PCB (board is in surprisingly good condition)
I have checked the sensor in the diff for the speedometer and it was fine however I replaced it anyway.
Fuel sender units seem okay no corrosion evident.

So now I am unsure of where to turn or what to do. Trawling through the forums has unfortunately yielded nothing as of yet. My hunch is maybe its a wiring problem to the cluster but I wouldn't know where to begin.
Any ideas or shared experience is more than appreciated, ta lads.

[Brianmoooore]

Fuel gauge and speedo. are independent of the SI board and its batteries, so you've been barking up the wrong tree there.
Have you taken the speedo. assembly out and checked the soldering of the pins that connect it to the main circuit board? These are the only soldered joints known to cause trouble with operation of the speedo.
Have you carefully checked fuses 10, 12 and 21, preferably by swapping them with other fuses of the same rating?
Remove the access panel to the fuel pump, pull off the three pin plug and use pieces of wire to short the brown/green and brown/grey wires to a good body earth. Turn on the ignition.
Does the low fuel light illuminate? Does the fuel gauge move?
Do you have a 55 litre or 62 litre fuel tank? 55 litre has a S shaped pipe joining the two sides of the tank together at the bottom. 62 litre tank has no pipe.
The wires from the speedo. sender arrive at the cluster on pins 6 (brown wire) and 12 (brown/red) of the white plug. A continuity meter connected to these wires should show continuity and open circuit several times per turn of the rear wheels - pushing the car a couple of feet is enough to test.

[aimlessrock]

Re the speedo have you checked the plug on the diff?.. This wiring suffered from the elements and vibration etc and the cables can fail.

HTH

[HDHD]

Thanks for the comebacks gents,

I have indeed had the speedo and fuel dials out and checked them over, I re-soldered the speedo joints anyway.
The fuses are working fine but I replaced them all with new units just to be sure and indeed I have already been down the dif sensor alley.
I will proceed later today with the test on shorting out the fuel tank sensors. (The fuel dial red light does not illuminate and it doesn't work at all)
Thanks again