Gas gauge troubleshooting...

[Aultro]

It's not working and is always on empty and never moves. I've tried two things at separate times.
1. disconnected the brown wire at the tank and and turned the key. The gauge went clear past full and stopped. Went back to empty when reconnected.

2. ran a ground wire to a stud on the back of the gauge and the other end to ground. nothing changed when I turned the key.

Anything else to try? Is my next option to pull the sending unit?

I've had the truck for about 3 months.

Thanks!

[kwmech]

Pull the sending unit and you will probably find a sunk or missing float

[Livrat]

Disconnecting the brown wire at the tank, turning on the key and having the gauge go past full tells me the gauge is fine and that your sending unit needs replacing or at the very least needs a new float. it probably got a corosion pin hole in it, filled with fuel and sank