77 fuel gauge not working correctly

[Ohio Bronco 21]

Recently just put this thing together, used a new fuel sender and the original 77 gauge for the fuel level. It only registers just below half when the tank is near dry, filling the tank gets it to about 3/4 of a tank. Stockk 77 style 14 gallon tank.

 

[krashnpa]

Hey Nolan, did you try disconnecting the sending unit wire and testing the resistance reading to ground? Or try grounding out to see if it affects the gauge level reading on and off ground?

 

[Ohio Bronco 21]

Hey Nolan, did you try disconnecting the sending unit wire and testing the resistance reading to ground? Or try grounding out to see if it affects the gauge level reading on and off ground?

I have not, good idea. I will try it. Should have some time tomorrow hopefully.

 

[Ohio Bronco 21]

I tried testing the ground with a wire to a better ground, still the same thing. Also I tried switching the ground and the sending unit wire and still got the same thing. My testing meter is mia for some reason (son), so. Not sure what is going on with it.

 

[krashnpa]

Haha the missing tool trick. I used to play that on dad all the time, now I just misplace things on my own and waste time looking for them.

Anyway, can you test directly at the gauge? If you pull ground (still need power), it should go to empty. If you apply ground, it should go full. That will rule out the gauge. I think I saw you refurbished the gauge, maybe something got disturbed.

If the gauge checks out, try a test wire from the gauge to the sending unit to rule out the wiring (you will have to isolate the current wiring).

If still nothing, the only thing left is a stuck or faulty sending unit.... which means pulling it to check or maybe finding that meter to test beforehand.

 

[thunderball]

I have this exact same issue and would love to see the solution if you come across it!

 

[Ohio Bronco 21]

Jury is still ut on this issue. It seems once I drove it more the sending unit started working, It may have been stuck or something (it is new). I will look in to it further.