Fuel gauge problem

[fgpope2000]

Can someone help me with a fuel gauge problem. I own a 1968 GTS and the fuel gauge works but is not accurate. I have tried 2 new fuel gauge sending units and the gauge will show full when the tank is full but when the tank starts to go empty it drops fast. The gauge will stop moving at 1/2 tank then will drop to empty and I still have 6 gallons of gas left. I have checked the tank ground for resistance and the gauge will move from full to empty when I vary the voltage to the gauge. Is the problem with the aftermarket sending units or am I missing something. Thanks

 

[67Dart273]

"Most of the problem" seems to be repop sending units. There's been tons about this on here, do a search. "Somebody" made a gauge calibration unit for sale, it's a deal that goes in between gauge and sender, and one of the members on here did some prototyping on one himself.

Possibilities:

Wiring / pc board connections problems

Instrument regulator / limiter out of tolerance

Gauge unit out of tolerance.

And.......the sending unit

Here's just one

http://www.forabodiesonly.com/mopar/showthread.php?t=264543