JD Fuel Gauge

[gringo]

I am having problems with the fuel gauge on my JD 3203. It only works when the tank is almost full and even then it shows half full. Once tank is below half full, it doesn't register at all. I removed the float assembly and everything looks good. I don't know if the gauge is the problem or the float assembly. Any suggestions?

 

[pmsmechanic]

Usually fuel gauges work by having a rheostat operated by the float vary the voltage to the gauge. If you take the positive wire from the gauge and touch it to the ground the gauge should go to full. If you remove the gauge and operate it with the wire or wires hooked up it should move the gauge from empty to full or vice versa. Doing those two things should enable you to figure out what the problem is. If the gauge goes to full when you ground it out then the problem is most likely the sender. If the sender moves the gauge through from full to empty then the problem might be gas in the float or else it isn't adjusted properly. Maybe someone who has a service manual can add their $.02 as I have no experience with this model and I'm just telling you what I would try.

 

[skyhook]

I removed the float assembly and everything looks good. Any suggestions?

It may "look" good but test bad.
Connect an ohm meter to the ends of the sending unit,then move the float up and down slowly,
resistance should change accordingly to the movement of the float.
If you get a reading of "infinity" ( no resistance measured ) when you go past half empty,
you have a defective sending unit, the rheostat is defective.

 

[gringo]

Thanks for the info fellas. Looks like I have a bad sending unit.

 

[mfreund]

If you disconnect the wires from the sender and connect them and disconnect them together you should be able to move the guage from full to empty. If the guage moves through the full range you would know for sure if it is the sender.

On my 4310 I know that when the guage needle is on full empty, I can put 5 gal of diesel in it.

 

[buickanddeere]

Dig out your multimeter and measure the ohms as the arm moves.