4210 Fuel Gauge

[mike48130]

I've read some posts here but have not seen any that are the same as my issue.

I just bought this tractor, and the fuel gauge was pegged to full. I looked in the tank and the float was broken off. I put in a new sender and it does the same thing. When I disconnect a wire, the gauge drops to empty. I went thru the service manual, and it doesn't say much more. I checked the resistance on the new sender and it is working and with in range.

So I did some experimenting, and I put some resistors inline with the gauge. If I add resistance, the gauge drops, but it needs more resistance to drop the gauge than the sender is capable of. The higher the resistance the lower the fuel gauge show.

So with about a 3/4 tank, I need to add about a 270 Ohm resister inline to get the gauge to read about 3/4.

This seems odd to me since if I had a bad connection or a corroded connector, the resistance should go up and the gauge should drop, but in my case here, I have not enough resistance because the gauge stay pegged to full.

I suspect the gauge is bad. It seems the gauge can only be replaced with a complete cluster. I checked the schematics and there is nothing to the circuit beside a ground and the wire to the gauge.

I think I might add the 270 ohm resister and see what happens when I go thru the fuel.

I was just looking to see if anyone else came across something like this.

Thanks,

 

[texasranger556]

My fuel gauge has spun all the way around and pegged against the rubber on the outside edge of the cluster. It was that way when I bought the tractor, I took the glass off the cluster and let the needle move back to the normal range. Then it did it again a year later. Fixed it a second time and it has been fine since.

In your case I would take the glass off the cluster and see if you can re-position the needle on the pin while moving the sender up and down the full range.

With the 270 ohm resistor installed, does empty read empty and/or full read full?

 

[mike48130]

I was thinking of looking at that as well. It seems to be consistent in the empty and full positions. I did not try the resistor empty yet. I could not play with the float and watch the gauge at the same time. I ordered a whole kit of resistors so I can simulate the empty, full and half points and see what it does. It seemed like a bunch of work to pull the cluster, but probably should. It looks like it fogs up too, so probably needs to be sealed.

 

[texasranger556]

It comes out pretty easy, less than an hour to have it out and back in.

Mine fogs up too, I might try some glass treatment if I have it out again.

 

[mike48130]

Thanks, maybe I will take a look tomorrow.

 

[mike48130]

I looked at it more and I think the gauge is jus bad. It seems to take about 600 ohms to move the gauge from empty to full. The sender is just 5-95 ohms. For now I will live with it until I can find a used cluster and maybe swap the gauges. Would like to keep the original cluster with the correct hour meter.