If you bench tested your new gauge before installing, then it's pretty simple to remove your sender and test the float.
With the float removed but connected, (use a jumper to your ground post), turn your key on, then manually move the float.
If it works, bend the arm a little.
If it doesn't work, buy the sender that JonG likes.
If you didn't bench test your new gauge first... use Pkak1's troubleshooting guide.
.
