Anyone know what ohms the sending unit should be , or range that it should be. With no wire on it, i was getting about 500 ohms with hot oil. The guage is deader than a door nail. I checked power and grounds. The sending unit is grounded. Also, when the wire is hooked up, i'm reading about 3 volts dc from the sensor wire to ground at the probe. I do not know what i should be seeing. Anyone been here before?