Fuel gauge stuck on FULL

Chip812 · Aug 28, 2011

When I got my MF35, the fuel gauge was disconnected (AND very old). It was marked as a 30-240 ohm gauge. I couldn't get it to work, so I ordered an original MF replacement sending unit (after-market, but touted as being identical in all respects) and a new 30-240 ohm fuel gauge... Every thing worked perfectly for about 2 hours, then the fuel gauge pegged at full and won't move until I turn it off (when off, it returns to EMPTY, so the gauge is not STUCK)...

I tried to test the sending unit, but with my itty-bitty, rinky-dink tester I couldn't figure out if it was sending 30-240 ohms (but the tester's needle did move back and forth when I moved the float up and down)...

So, does anybody know if the 30-240 gauge is compatible with the MF sending unit? (The tractor place where I bought it said, "Yes, it is.")...

Does anybody know how to fix this particular issue? Do I need to put a resister in the wire or something?

Thanks.
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Chip812 · Aug 28, 2011

P.S. Forgot to mention that [i:95d0e62e60]even with the sensor wire disconnected[/i:95d0e62e60], it still reads full when I turn the key on... :shock:
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Chip812 · Aug 28, 2011

Well.... !#@$#@#$@!#$%*(($.... Don't you just hate it when you take everything apart, can't find anything wrong, put it all back together while you wait on an answer from The Wisdom Of The List, and the dang thing starts working... perfectly... ??? Oh well, such is life... I just wish I knew [b:ba85591868][i:ba85591868]exactly[/i:ba85591868][/b:ba85591868] what the issue was in the first place so I wouldn't have to take EVERYTHING apart next time... :?
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P.S. I suspect a short-to-ground, but for the life of me, I can't figure where it was happening... ???

Chip812 · Aug 28, 2011

Well... 4 hours of rough-as-a-cobb bush hogging and the gauge still works... Anybody know how long a MF35 will go (at pto speed) on a tank of diesel (3-cyl perkins)??? I just did 4 hours and maybe used a quarter tank of fuel... ???
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garymck · Aug 28, 2011

The only comment I can make is on my MF 35 gas, I just replaced the gauge and sending unit but the unit would not work until I grounded the sending unit back to the battery. I guess it had lost it's ground through the tank. It has been installed just a couple of weeks and so I hope it continues to work.

Chip812 · Aug 29, 2011

I had to ground mine as well in order to get it to work... From the looks of the sending unit, it looks like it is electrically isolated via the rubber washers on the screws and the rubber gasket on the sending unit... Wonder how the original worked, because it was also isolated... ???
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Alont · Aug 29, 2011

Your fuel gauge MIGHT work like this, although the
resistances may be different.
It does make the gauge read FULL with an open cct
sender.

http://mgaguru.com/mgtech/electric/fg_05.htm

Fuel gauge stuck on FULL

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