Instrument (a/k/a Constant) Voltage Regulator

[Lee]

At least for 1968, my Cougar manual called out substituting a 10 ohm resistor for full, and 73 ohms for empty. I'll bet that worked across the board.

[Dan Szwarc]

That’s probably right.

[frasern]

Just a thought, bear with me. I could not get a sender for my diesel truck and I had to fabricate one, I used a number of old and damaged ones until I found usable parts. What I found is, they all have an inside wire from the rheostat, to the mount, but the coating is different coloured for different applications, this seems to be a resistance wire. I concluded that the rheostat and wire form a specific resistance for that gauge, but that is just the thought of an unqualified layman, not an EE.

[RMAENV]

The 10 ohms - full, 73 ohms empty are the measurements of the fuel float in the Lincoln tank. Las time we changed mine we used those to adjust the arm on the float before we installed it. It is pretty accurate.