Tahoe deckboat fuel guage always on full when key is turned on

[shassell1]

new 2021 Tahoe 1950 deckboat

The fuel guage always reads full once you turn on power. I checked the sender and it is showing different resistance if sender slide is at top or bottom so seems like it is good. This is 2nd guage.. View attachment 349230fuel guage is brand new replacement from dealer. It has ground between in and other guages. Anything else to check ?

On guage connection: S = pink. Ground mounted in Center, I = purple, L=purple

 

[dingbat]

If your positive you have ground, then obviously you have an issue with the sender wire.
Put a meter on the gauge and see if you get a resistance change at sender