People ... ground connections ... go back and read my posts ... two sides to a circuit -- supply to device and ground back to battery through the body/chassis metal.
Clicking noise? In dash? There's a second voltage regulator in the instrument panel for changing 12 VDC to 5 or 6 VDC for the gauges. Older regulators were a form of relay that made a clicking noise when working. If yours has the older type instrument voltage regulator, the noise is normal. (You usually can't hear it because the running engine drowns it out ... only evident when key is in RUN position but engine isn't running.)
Oh, yeah ... good job troubleshooting fuel gauge issue.
