Gas gauge question ?

[js27]

It has been a while since I actually worked on a car and Forgot a lot. My 67 Satellite gas gauge is not working ever since I pulled the dash to restore it. I do not believe it was very accurate to begin with because it was reading 1/2 a tank and I went to fill it and got about 4 gallons in it before it started to spill out. These cars have a 19 gallon tank so I do not think 4 gallons would fill it from 1/2 a tank. I bought a new sending unit with plans on replacing it. After I got the dash back together everything works fine but the gas gauge so I thought the sending unit bit the dust. I had that happen on my Challenger. One day it worked and the next it didn't. Replaced the sending unit and it worked fine. SO I crawl under the car to replace the sending unit only to see a brand new shinny sending unit and lock ring. I called the previous owner and sure enough he had replaced it. There was no ground strap on it like there should be but it was working. I order a new ground strap for it yesterday. My question is am I doing this correctly--I pulled the wire off the sending unit and grounded it to the gas line and also tried the frame while the key was on and the gauge never moved. Does this mean it is in the gauge and not the sending unit ?? If so what could be wrong with the gauge ? There is only one 4 prong plug that connect to the gauge and I cleaned all the contacts areas before re installing it.
Thanks
JS27

[Bullitt-]

You can ground the wire that connects to the sending unit to see if the wiring & gauge are working... gauge should peg. If it does then you know the issue is with the sending unit, if not you have a problem elsewhere.

[Rich G.]

If it's like the e bodies the rear harness connects behind the kick panel. I would check to see if you have continuity from there to the sender wire. Then from there to the gauge.