Fuel gauge

Justin Post · Apr 30, 2012

Every tractor i own with a fuel gauge doesn't work. I dont understand how the sending units work. Anyone care to give me a lesson on where to start to work on them. I have a Massy 97 super 90 and a 88. I also have a ford truck and a case 1845 that doesnt work. I just use a stick but it gets old. Thanks

JMOR · Apr 30, 2012

(quoted from post at 17:23:09 04/30/12) Every tractor i own with a fuel gauge doesn't work. I dont understand how the sending units work. Anyone care to give me a lesson on where to start to work on them. I have a Massy 97 super 90 and a 88. I also have a ford truck and a case 1845 that doesnt work. I just use a stick but it gets old. Thanks

Remove one from tank & play with it..........most older gauge senders are just a variable resistor where the wiper arm is attached to a float. As fuel level changes, float follows and moves resistor wiper across its windings of fine wire, so resistance goes from high to low or just the opposite on others as fuel is used. This resistance change causes a current change which is read by gauge on instrument panel.

John730D · Apr 30, 2012

Here ya go
More than you wanted to know

Larry NEIL · Apr 30, 2012

Most of my fuel sending unit problems stem from a bad ground.

fixerupper · Apr 30, 2012

Ground the wire that connects to the sensor and see if the gauge moves. Most of them will read full when the wire is grounded. If the gauge works, the problem is in the sender. Either it's bad or it's not grounded to the tank well enough. If the gauge does not move, the sender wire might be broken or disconnected (unlikely). If the sender wire is connected and not broken, the gauge is bad or not getting power. The gauge doesn't seem to go bad that often. Usually it's something else. Jim

JMS/.MN · Apr 30, 2012

My experience too- take the wire off the sensor, touch it to ground. If it pegs the needle, the sensor is bad.

Chip812 · Apr 30, 2012

Mine didn't work when I got it either... Bought a whole new sending unit... but didn't need it... new unit wouldn't work either... However, when I put a ground wire on one of the screws, it started working just fine (I guess the tank must, somehow, be insulated from the rest of the tractor)... I would try grounding the sending unit first... Might work for you too...
8)

RalphWD45 · May 1, 2012

I bought an Allis CA last year, that has the most accurate fuel guage, I have ever seen! Previous owner, brazed two 90 deg brass elbows to the tank, one on the bottom of the right side of the tank, and one straight above it, on the top of the tank.He connected a 7" clear plastic hose to the two nipples on the el's, and made graduated black rings around the hose to show fuel level. It works good, but the hose is getting kinda yellow.

Blackhole49 · May 1, 2012

Also, make sure the float is still on the sending unit. On both my boat and Kubota, the float vibrated off.

Fuel gauge

Justin Post

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JMOR

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John730D

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Larry NEIL

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fixerupper

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JMS/.MN

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Chip812

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RalphWD45

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Blackhole49

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