[Dan in Pasadena]

So I'm trying to figure out the Dakota Digital HDX gauge. I filled her up today and gauge reads a little less than 1/2 tank. I'm wondering if it's as simple as the guy that selected which GM ohm setting to use, selected 0-90 and it should have been 0-30? I'm no sparky so if anyone has a comment, feel free. But if 90 ohms = "full" then wouldn't a full tank register as less than 1/2 because 45 ohms would be half with that type of sensor?

Reading through the instructions (We don't need no DAMN instructions! ha ha) there is also a potential issue that there's supposed to be a separate ground run from the sensor mounting plate to the frame. I'll have to get in there and check but I THINK the two wires to the sensor, one went to the Signal terminal and one went to a ground ON the sensor mount plate, nowhere else.

Anyway, figuring this out and hoping nothing gets damaged til I do. All comments/suggestions appreciated.

EDIT: Sorry about the pic being sideways. If anyone can decipher more from this than I can please tell me. There's also a question (to me) why it says two "twisted" wires? Why would twisted be important or am I being a dipsh!t and twisted means something else here? A picture of the sender wiring added if it helps shed any light. To my non electrical-saavy eyes it looks like the in-tank fuel pump and sender grounds are connected together and grounded to the pump mounting flange. No connection to the frame which the instructions SEEM to clearly say is required. Opinions?