diagnosing a non-working fuel gauge on zd28

[jcansler]

I have a kubota ZD28 with 107 hours and the fuel gauge has stopped working. I would appreciate any advice on diagnosing the problem and fixing it. Thank you..

Joe

[Stumpy]

It's a fuel gauge, even when it's working it isn't! I just look in the tank everyone once in a while more accurate than those things.

Lose any other gauges or just fuel? The tachometer should be mechanical so that will work without power. Check the dash fuse(s) first. Then I'd wiggle the wire leading to the gauge and back to the sender. Failing that if it's still under warranty I'd get it in to the dealer quick before grass season gets here. That is unless you've a handy type and feel like tracing wiring.

[jcansler]

Thank you Stumpy. I have an electrical sensor breakdown and it appears unless it is a loose or corroded connection it has to be the fuel sensor in the tank or the gauge itself. Because the mower only has 107 hours I would like to repair this, but I'm not sure what to check first so anyone who could advise me on how to trace down the issue would be greatly appreciated...

Joe

[lreops]

Not sure if this is applicable, but could a stuck float be the cause? Where is the gauge at now? Is there any movement at all with the gauge when you switch the key on and off? I've seen some floats that when bouncing around, get a little cocked and hang up, usually temporarily.

Just a thought and my 2¢.......keep the change

Ron

[jcansler]

Ron, thank you for your response. I checked the float and it moves freely up and down. It does not have any effect on the gauge reading which reads empty regardless of the float position and the gauge reading does not move at all when the key is switched on and off. Any suggestions on troubleshooting this issue will be appreciated... Thank you...

Joe

[Stumpy]

Alright then. Nearly all tank senders are potentiometers acting as variable resistors, meaning they change the resistance in the sending wire as the fuel level varies. The gauge circuitry reads this and moves the needle proportionally. To confirm that's working properly get your multimeter out and remove the sending lead from the back of the gauge. Hook it up between the lead and ground and set the multimeter to the appropriate ohm range. Once you've got a steady reading in the right range move the float up and down and see if the resistance changes. That'll answer that question.

If the sender is operating properly make sure the gauge is getting power and if it is then replace your gauge.

A generic diagram of the system I found on the interwebz:

[jcansler]

Thank you Stumpy, I think this is what I needed to find which unit is bad. Thank you for the instructions on how to diagnose the problem...

Joe

[whitetiger]

To check for the failure cause, remove the left hand fender to gain access to the sender. With the key in the "run" position, unplug the wire from center of sender and touch it the stud that has the ground wire on it. If needle goes to full, sender is faulty. If nothing happens, using a jumper wire, jump the push-on sender wire to a ground on frame. If needle does not rise, plug wire back to sender and using your jumper wire go from frame ground to a stud on the sender.
If your gauge does not rise, remove the right hand fender to gain acccess to rear of gauge. You will need to remove a cover. Make sure the wiring is plugged tightly onto rear of gauge.
Failure is usually the sender or the wireing plug comes off rear of gauge.

[whitetiger]

Originally Posted by Stumpy

It's a fuel gauge, even when it's working it isn't! I just look in the tank everyone once in a while more accurate than those things.

Lose any other gauges or just fuel? The tachometer should be mechanical so that will work without power. Check the dash fuse(s) first. Then I'd wiggle the wire leading to the gauge and back to the sender. Failing that if it's still under warranty I'd get it in to the dealer quick before grass season gets here. That is unless you've a handy type and feel like tracing wiring.

ZD series mowers do not have a tachometer.

[jcansler]

Thank you for your response. This is what I needed, how to diagnose which was bad the sender or the gauge. Thank you again....

Joe