Hi and welcome to the forum
Have you tried running a separate earth from the sender to the body, I would have thought a dodgy stabiliser would cause the gauge to wander at different engine revs, but if all else fails
Thanks, been lurking for ages but not got round to posting. Most things I have found by searching.
If I earth the cable to the petrol tank it showed full so the earth to the tank is good.
Anyway I have got it working now. I lost count the number of combinations I tried.
I figured out the wiring was fine so it must have been a combination of other things. Three fuel senders all gave the same 1/2 reading when connected with everything as it was. So I assumed it must be at the gauge end. Had tried a different stabiliser and fuel gauge with no different. Then I tried the different stabiliser and gauge together and it shot up to 3/4. So after slight adjustment on the fuel sender arm I have a gauge that read from empty to full.
Time for a beer