MF 275 temp and fuel gauge wiring

[peachfarmer]

Just bought this tractor Im saved the wiring issues for last. fuel gauge and water temp gauge do not seem to be working. According to the shop manual there should only be two wires on the water temp and fuel gauge the led wires going to the sensor and a jump wire from each of the gauges. On the back of the original gauges there is a letter S and a + sign I think some one has hooked the wires up wrong both the fuel sensor and water temp sensor are reading good continuity, The original wire going to the sensors have been replaced. What does the S stand for and any though about the correct wiring sequence. thanks

 

[travlitt]

Probably S terminal to sender would be my thinking.

 

[skyhook]

Probably S terminal to sender would be my thinking.

Yep, the "S" terminal is for the sending unit in the tank.
You should have two wire connections from the tank, one goes to ground and the other "S" wire goes to the "S" terminal on the gauge. You should have about 3 to 300 ohm reading between the two terminals "on the tank" sender (depending on how full your tank is).