Fuel Gauge Voltage

Ive got a problem with my fuel gauge only reading half tank when I fill it up. I have checked the voltage going to the sender unit and found to be only six volts. After reading previous posts it looks like it should be 12V ? But when I remove the earth wire from the back of the gauge the voltage goes up to 12v supply to sender. I have tried earthing directly but the voltage is the same. I have removed the gauge and tested it on a battery and is reading empty to full with no problems. Any ideas ???

I had a problem with my gauge a while back, it was reading empty all the time. I checked electrics as you did and the gauge was fine, so I pulled out the actual float contraption in the tank and played with that for a little, put it back in and it worked fine... so maybe pull that out and slide it up and down and it may work.

I have already pulled the sender out the tank to check if the float is stuck but its working ok. Is the sending supposed to be getting 12v supply ? There are three connections on the sender I know one is the supply from the gauge does anyone know what the other two do ?. I have read somewhere there is one for low level indication on the gauge. I have changed the original 200tdi bulk head with a newer model (300tdi or td5 not sure ) but have the original sender and fuel tank.


Anyone got a idea ???

Thanks

Anyone got any ideas ??

try to play a little bit with sender needle it might not be making a good contact