Hello, the fuel gauge on my 1850 gas bounces between E and the current tank reading. From what I can tell the reading is actually correct (changes as the tank level changes) just bounces back to E and back again. I made sure the connection was good at the sender when I last had the hood off. Does the bouncing indicate gauge or sender problems?

Some additional questions on the gauge, for an original two terminal gauge, should there be any internal ground connection for either terminal? I'm guessing not, but I've got continuity between the battery terminal and the gauge case when testing with a multimeter.

I see some of the replacement gauges use three terminals with one for ground, but is that for the light and not for gauge itself? Curious if the newer ones are wired differently. Also the backlighting must be internal (no longer plugging in the socket)?

Thanks.

FIRST make certain the tank is tight on it's base. It needs to be grounded.The gauge operates on a "completion of ground" electrical circuit. Take a piece of sand paper and shine up a spot on the tank and a spot on the tractor frame. Hook a jumper to those two spots. If the problem goes away install a permanent jumper from one of the screws that hold the sending unit in place and a spot behind the dash that will give a good ground. Make certain all connections are clean and tight.If that doesn't do it go to the next test. Take the hood off. Remove the sender. Ground it to the tank with a jumper. Turn on the key and by moving it in different motions see if you can duplicate what you are experiencing on the gauge.

I bought a new sender from AGCO for my 1650 and it is a newer style without the old style rheostat. Works nice.