I have about 1/4 tank of gas and the fuel guage reads 3/4. And when the engine is 170ish, the temp guage also reads about 3/4. I can ground their respective sender input leads and each guage will go all the way to their respective max. So the guages appear to work fine.
I just thought it would be easiest to experiment with a lower voltage to the guages, since they both seem to be a bit high. But then, I know little to nothing about this subject.
