1941 Chevy 1/2 Ton Pickup

Facts:
The truck has been rewired with harnesses from Rhode Island Electric. There is a new gas tank as well as a new sending unit (tested). The guage reads in the reverse. That is, when float is raised the guage will move toward empty. If I ground the sender wire it will move toward full rather than empty as it should.

In desperation, I even reversed the wires on the guage. Nothing changed. Same situation.

I'm at a loss. Need help badly!

Thanks,
Ed