UPDATE!

Ok- Had a gauge and sending unit from a 70 satellite to check things out as a double check!


Double checked the OHM's from both gauges. - 10 empty, 70 full I believe on both

Wired the satellite gauge up and it worked fine - out of the car but from the plug and ground at the tank.

Pulled the front seat to get to the back of the gauge and checked from there:

Had the sending unit in the car with jumper wires, to eliminate the wire from the gauge to the sending unit and it didnt work. Jumped in the satellite gauge ( after voltage reducer, before gauge ) and it worked.
Plugged the wires back and ran a jumper wire from the outlet of the gauge to sender and it didnt work.

This sounds to me that the gauge is dead. Even though I can make it move with 12v by grounding out the sending unit wire at the back of the car!

WHEW!