MF1010 fuel gauge not working

[handirifle]

Truth us, it never has in the 13 yrs I have owned it. I would like to resolve that, but I know very little about the systems. Not 100% sure how they work. So I would greatly appreciate any insight on how to troubleshoot one. For the last 8 or so years, I have used one of those spiral gauges from a lawn tractor, but it finally became fuel logged, and sits at the bottom now. I ran this thing out of fuel once, a long time ago and have no desire to repeat history.

Suggestions on where to start? Not sure where the sending unit even is?

Thanks

 

[beowulf]

The only time my fuel gauge stopped working was because mice had chewed through some wires. Just a thought. I don't know if that is your issue.

 

[handirifle]

Well, its a place to start. Any idea where the sending unit is located on the tank?

 

[Jerry/MT]

Truth us, it never has in the 13 yrs I have owned it. I would like to resolve that, but I know very little about the systems. Not 100% sure how they work. So I would greatly appreciate any insight on how to troubleshoot one. For the last 8 or so years, I have used one of those spiral gauges from a lawn tractor, but it finally became fuel logged, and sits at the bottom now. I ran this thing out of fuel once, a long time ago and have no desire to repeat history.

Suggestions on where to start? Not sure where the sending unit even is?

Thanks

The circuit is generally from the BAT connection on the key switch to a voltage reducer (generally limits voltage to 5 V) to the sending unit in the tank to ground. The system is basically a variable resistance (tank level sensor) that has a high resistance when the tank is full to a low resistance when the tank is empty. The current heats a small bimetal coil that causes the needle to move. So a full tank has a small current and empty tank has a high current. If you MOMENTARILY ground the wire that connects to the sensor, if the circuit is complete to that point the needle will go full scale. If that happens, the sensor or the sensor ground is bad. The sensor ground is through the sealing ring threads to the tank. Make sure the tank has a good ground and check the sensor for continuity.
Hope this helps you.