801 powermaster fuel gauge and sending unit

Travman

New User
I just bought a new fuel gauge and sending unit for my 801(841) powermaster. With power wire ran, ground ran, and wire to sending unit from gauge. Gauge stays on empty. I can take off wire to sending unit and gauge goes to full, and I half a half of tank of gas. Please help, I need all the help I can get as I am new to this. Thank you.
 
Typically, the gauge should read full when the sender wire is grounded, empty when the wire is not touching ground. But, there are exceptions, some work the opposite.

An easy test, remove the sending unit, ground the flange, connect the gauge wire. Then move the float through the full movement while watching the gauge. Some gauges have delayed action to prevent bouncing the needle as the fuel sloshes, so allow it some time to react.

If it responds correctly, take some measurements inside the tank, adjust the float accordingly. You want to adjust it for accuracy at the empty level more so than the full. Be sure the sender is turned to the proper position and the float doesn't touch the side of the tank.

If it doesn't respond, double check your wiring and battery polarity. If it still doesn't work, or responds backward, there is a problem with the gauge or the gauge/sender compatibility. Be sure the gauge/sender you ordered is the correct voltage and polarity for your tractor as it is now wired.
 
I did remove the sender and tried that, but with the same outcome. I bought these parts and several others at a local shop with no problems with any of the other parts. I checked the ohms and while moving the float up and down the ohms where also going up and down. I feel the parts should be good, but like I said I am new to this and hopefully I just have something wired wrong or not grounded. I messed with for a long while today and had to step away...lol. Thank you for the help though.
 
With power wire ran, [b:654c4848f0]ground ran[/b:654c4848f0], and wire to sending unit from gauge

Do the instructions say to run a ground wire because the sending unit is usually the ground.
Power runs from the battery to one side of the gauge; threw the gauge out the other wire to the sending unit.
The ohms increase as the sending unit arm moves giving the wire more or less ground thus moving the gauge.

You can take the wire off the sending unit and gauge goes to full.
Does it go to empty when you ground the wire to metal?
If so the gauge is working.

How long is the arm on the sending unit?
Could it be at its full extent down reading empty.
In other words it is for a shorter tank. Tank is to tall.
Measure the depth of the tank and where the fuel is at.
Then with the sending unit out and grounded move the arm to correspond with these depths and see what it reads.
Try it at full; where fuel is now; and empty or bottom of tank.
 
(reply to post at 23:19:28 07/1
4/18)



The arm is the same length as the old, but the old one has never worked since I got it. I watched a video on how to check the sender outside of the tank. Hooked up all the wires, and ran a ground to the sender. Video showed gauge going up and down with movement of the float like its suppose to, but mine did the same thing as it did when it was hooked up in the tank. Stayed on empty until removing the sender wire, then went to full. Still not sure what is going on. Thank you for the help
 
I believe that tractor had 2 different electrical systems, a 6 volt positive ground on the gas models, and 12 volt negative ground on the diesel.

If the parts are not specific for the correct polarity and voltage, or if the 6v has been converted to 12v, it will not work.

Might question the parts supplier about this, see if they show different gauges for different systems.
 
(quoted from post at 13:55:12 07/15/18) I believe that tractor had 2 different electrical systems, a 6 volt positive ground on the gas models, and 12 volt negative ground on the diesel.

If the parts are not specific for the correct polarity and voltage, or if the 6v has been converted to 12v, it will not work.

Might question the parts supplier about this, see if they show different gauges for different systems.
It is still a 6 volt system, and the parts say 6 volt. I am definitely gonna contact supplier tomorrow to see what is going on. Nothing I've tried seems to be working. Hopefully a bad gauge or sender. Maybe the two are not compatible. Sorry for delayed response had to work. Thanks for the help.
 

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