Greg,
Thanks for your thoughts. Yes, this is the issue I have. Without any screws securing the unit to the tank the sending unit works correctly. When I put one screw in the resistance to ground decreases, with 2 screws holding the unit to the tank, the unit is totally grounded. I have used the slop in the mounting screws to move the unit, but have not been able to get out of the situation. Will relook the situation, it is puzzling.
