Fuel Gauge

[pdawg]

I need some help with a non-functioning fuel gauge. I printed a trouble shooting guide that was great, but still don't have a clue what's up! Removed wire at the tank & gauge goes to full. Grounded send unit wire & gage goes to empty. I have replaced the send unit (twice) but I checked it with an ohm meter after removing it again, just to be sure, & it checks out ok. I have tried grounding the sent unit, checked voltage at the gauge, grounded the gauge & still can't figure it out. Anybody know if I'm missing something? It would be most helpful to have a working gauge while trying to tune the Holley carb on my new motor (that's a whole other saga!) Many thanks!
Perry
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Posted via Mobile Device

[jdm0068]

I had this problem. It turned out my float didn't float any more. I took one off another sending unit and attached it to the sending unit for the truck for a short term fix.

[pdawg]

I guess I've checked everything else so I may as well pull it out and try that. It was a new unit so I assumed it would be good, but you're right - I should check it. Thanks for the suggestion!
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[VetteVet]

have you checked the sending unit flange to tank ground and the tank to frame ground?

[Dnrice]

Where are those grounds? Mine shows full almost all the time and then when close to empty, it bounces around.

[cool68]

I have not found ground wires from tank to cab - where to look? another thread says to be sure that the gauge cluster is grounded to cab. something about resistors in gauge also.

[pdawg]

Thanks for the reply! I couldn't find a ground from the tank to the cab, but it is bolted in several places - so I just ran an extra cab to chassis ground to make sure. I've heard about the resistors on the gauge cluster too, but I want to pull the send unit and physically move it through the motion ( while grounded ) to see if I'm getting a reading. I've heard of floats having tiny holes in them, even when brand new! Hopefully our weather holds out hear so I can check it out before storage time!

[CBrown680]

My gauge had the same issue. I checked the ground, especially at the door jamb, found out it was the float. It had a pin hole and was full of gas! Ordered a new plastic one from the parts house. Believe it was for a jeep but it worked out great! Hope this helps!

[pdawg]

Thanks for the tip! I knew I saw a remark about the pinhole in the float before! It likely was you! Whatever would we do if these problems didn't keep popping up! God forbid we would just be able to cruise in our projects!

[Don Quixote]

I had the same issue and after much troubleshoting, I found it was an invisible pin hole in the float. A new one was backordered but a heart medication bottle worked well until my new float came in!

[pdawg]

Thanks for the tip! Wow - that is being resourceful!
I'm going to pull my sending unit out hopefully this weekend @ see if it registers properly while manually cycling through the motions. I'll post the results.