Fuel Gauge

turklilley · Nov 14, 2015

I have a fuel gauge for a 2000, 4000, 601, 701, etc. I'm trying to adapt it to a John Deere, because it is negative ground. It has 3 terminals on it. Does anyone know which terminals go where? Only one is marked -, that is on the right hand looking at the back of the gauge.

Mike Groom · Nov 14, 2015

Normally you would have a + wire,- wire and the sending unit wire from the gauge in the tank.Black is usually neg.,red positive and the sending unit wire could be white or almost any other color. Hope that helps.

Tom in TN · Nov 14, 2015

Turklilley.

I just installed a new fuel gauge on my old-style 4000 tractor. It's a negative ground. The gauge has three wires on it. One is a ground wire to insure a good ground to the outside of the gauge. One is a plus voltage pin that is turned on when the key is on. The third goes directly to the sending unit. The sending unit is just a plain old rheostat that varies the amount of resistance between the wire that goes from it to the gauge and the fuel tank/frame/ground. As the fuel rises and falls, the amount of resistance presented to the gauge via the wire from the sending unit to the gauge, rises and falls.

I said all of that to say this: the two posts that are positioned near to one another are going to have the plus battery voltage from the switch on one of them, and the wire from the sending unit on the other one. The third post will have a good ground on it all of the time.

Good luck with your installation.

Tom in TN

RodinNS · Nov 14, 2015

On a gauge of that nature I don't think it matters. Most gauges I've dealt with are one wire and ground through the body of the gauge. If it's a two wire setup that is isolated from the chassis then just use a meter to see which terminal is connected to the body of the gauge and hook that as the ground wire and the other one to the gauge. In reality tho, the only way it would matter which way it's hooked up is if there's a diode in the sender or the sender is using two wires and not isolated.

Rod

Sean in PA · Nov 14, 2015

In addition to all of the above, are you using a Ford sender that has the proper resistance range that the gauge expects? Or are you using the JD sender and hoping that they are compatible? I wouldn't expect a Ford sender to fit in a JD tank, but you never know. And likewise, I wouldn't expect a JD sender to have the correct resistance range for a Ford gauge, but again, you never know.

Fuel Gauge

turklilley

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Mike Groom

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Tom in TN

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RodinNS

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Sean in PA

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