Back with a question on the fuel gauge. It works... sometimes. Seems to have a mind of it's own. When it's not working it indicates 'Full'.

I figured it was a fuel sender problem and replaced it. Problem still not resolved. I verified continuity from ground terminal to the chassis ground...looks good. Verified DC volts at connector with ignition at on position.

I'm at a loss... any thoughts?

 

If the problem did not go away with the new sending unit, then the fuel gauge in the cluster is the culprit.

You can take apart the cluster and check for bad solder joints and/or corrosion where the gauge has connections to the cluster circuit board.