sorry i didn't let you know any of the info, who knows what i was thinking. 1963 chevy c10. the under bed tank and sender unit are from lmc truck. it was a little different than the ones i have ordered before like i have on my 64. it had a threaded post to hook the wire from the gauge to. this one had the ground wire but the post wasn't threaded so i just crimped on a connector. the tank is sopposed to work on 60 to 66 i thought. i switched out the dash cluster and thought that would fix the problem, but i don't know for sure if it's the gauge or not. i tried hooking up a 64 to 66 gauge i had around same thing.
it reads whatever then when i turn key on it goes to empty. my 64 does this it read 3/4 all time them when i turn on key it goes to proper location. soooo i am not sure if its the gauge or what. i also used a larger gauge wire to go to the tank, mabey that's the problem.