[AdamIsAdam]

Thanks. I get it. I'm just having trouble getting decent, consistent readings. I do seem to be getting consistent OHM readings at the tank of about 34-36 with a nearly full tank. That seems correct for the 1964 sending unit.

I'm getting about 12v into the gauge. Where it gets fuzzy is the line out of the gauge to the tank. I can't get a good contact on it (while laying on my back, reaching up to the back of the gauge) to ground it out in an attempt to get that gauge to read E. But next attempt I think I'll get a wire on that post, then plug the harness back in on top of it, then ground that wire to get the gauge to read E. (The harness on the gauge is a L shaped plug, so both B+ and the output to the sending unit get plugged in as a pair.)

I bought a new multimeter and was getting very inconsistent volt readings out, but that's because I couldn't get a good probe connection I think. As you can read above, I was getting about 2.8v out before, but it was dropping to around .8v by the tank. If that is in fact the case, my problem should be along that wire.

So if I can run a jumper off the gauge, I will be able to do two things: check gauge by grounding it, and then run that wire directly to the sending unit which should then read accurately.

That's my game plan. I plan on executing it tomorrow evening.