I confess - I jumped the gun and installed a new fuel tank sender today hoping that would solve the problem. It did not! My bad.
Went back to basics: wiring, first looking again at the ground wire, which I re-wired again, and looked for and found a different place on the tank to try for a ground. Cleaned the area around one of the screws to the gas filler pipe, a last ditch effort, made the connection, and viola, the gauge now registers 1/2 full and goes to empty when I turn the ignition key off --- just like it's supposed to. Lots of learning in this process, and I went back and read again the many times that many of you stressed: the ground is often the prime suspect.
My many thanks to all of you who have given so much good testing advice to help me get to here. I am very pleased to have a working gas gauge (without having to replace the gas gauge!).
Dale
