Fuel Gauge Issue

[‘Ol Flossie]

I have a 1984 C10 with a fuel gauge issue. I’ve read many forums and it seems as though this is a common issue, but I've not been able to resolve by the testing and suggestions I’ve read about. My fuel gauge reads properly while not moving, but when accelerating the fuel goes to the rear of the tank, it reads full. When going downhill or braking, fuel goes to the front of the tank and gauge reads empty. Driving along after it settles, fuel gauge reads accurately. I’ve gone to the junkyard and collected a variety of ceramic resistors, from 80 - 125 ohms. None of which seem to work for me when I install across the signal and +12 volt terminals of the gauge. The gauge reads full, as if the resistance is too high. I feel as though my sending unit is good. With the tank half full, I get a reading of 45 ohms from the sender to the pin on the main harness connector going to the dash cluster, specifically that goes to the fuel gauge sending unit terminal post. Ive performed a continuity test to chassis ground of the gauges grounding terminal pin at the main cluster harness successfully. Supposedly from what I’ve read, the ceramic resistors were to dampen the fuel Sending unit signal for sloshing, but when I installed resistor, the needle goes past full as if there were infinite resistance/no ground for the sending unit. I don’t recall this happening with the original fuel gauge that I removed and replaced with a tachometer, which I can’t find to test with. I’ve tried two different new gauges with the same result. As well as replacing the tank and sender. I replaced the original sender and tank because of rust in the tank, and then replaced the tank and sender again when I converted the carb to fuel injection. Sender is a 0-90 ohm sender. Anybody with any ideas on what I’m missing?

[Bandit130]

This could be the issue with your fuel gauge.

https://www.youtube.com/watch?v=HuGfmgNPTS0

[Honest Bob]

I found this video to be particularly informative.
https://www.youtube.com/watch?v=LRQU7chppLg

On my blazer I had two issues. It would work randomly and go way past full.

1. Loose fuel sender connector located in the middle of the truck (little rubber connector).
2. A fuel sender that tested bad at first, but got working with some tinkering. Ended up replacing it.

You really need to inspect every inch of the wire and clean all the connectors/grounds. A loose connection anywhere in the circuit is adding more resistance which may be causing your issue. If its going way past full that indicates a break in the circuit and can also be in the fuel sender if its not working properly.