as far as i know, most of the fj40s have a three post fuel gauge. one for power, one for the sending unit, and one that gives power to the thermostat. on the inside, there are two thermo "blades" one acts to measure fuel, the other acts as a switch and even has an adjustment screw on it. my question is, what is the point of the switch? it's directly grounded, so, once it heats up it opens and causes a loss of power to the thermostat and the fuel gauge. why have it?