sending unit or fuel gauge

alright i just tried posting this but it didnt show up anywhere sorry if it posts twice. i have a 2001 dodge ram and i put a 19 gallon rci fuel cell on it and mounted the stock pump to it. the fuel gauge is always saying it empty. if someone can shed some light on the subject or a way to fix it that would be appreciated

did you mount the entire sending unit or just the pump?

the sending unit is measured in ohms to produce the reading on your gauge take the sending unit and a digital ohm meter and measure the ohms as you move up and the float  but make sure you call dodge and find out what the reading suppose to be 140 to 260 ohms or something to that nature it could just  be a bad sender  but if you didnt install the sending unit in the new take just the pump aaaaaaaah that the problem

make sure the sending unit is grounded. if it is an aluminum tank it is not grounded.

the entire assembly is installed on the cell. it is an aluminum tank but the factory tank is plastic so how would that take the ground away from the sending unit.

if your sending uinit is the same as the 98s,i wana say empty its at 90 ohm.and full is 150 ohm or something stupid like that.cuz its way off in comparison to the gm ones.and i belive the ground is ran in the harness.i know mine is,or was..lol