I did all those tests, I think I have it working now except it does not go all the way to empty when grounding the sender wire. but with the new sending unit it does go up and down, I did test it first and it read 0 ohms at empty and 30 ohms at the full mark. The gauge just wont read all the way to empty. Even when I tried the new unit outside of the tank. it read over full when the float was all the up and around 1/4 tank when the float was all the way down. Is it just an inaccurate gauge due to cheaply made replacement gauges? Let me know thanks Mike