Gas Gauge not working!!! What to check?

[MykeNytemare]

Hello all,

The gas gauge worked in the past (though not well). Over the last 2 years I have done a lot to the car restoring it and now it is up and running almost 100%. However, the fuel gauge doesnt read at all and I have to carry a gas can for longer drives.

I checked the grounds to the sending unit (tank was replaced but I kept what I thought was the stock unit) and even bought 2 other sending units including a Spectra. It seems that the resistance/readings of all 3 are different and I am wondering what the range should be on a 1967 Coronet.

At least if I know what it should be I can make sure I have the right sender otherwise I know my issue is at the dashboard with the actual gauge.

Any help in troubleshooting this is appreciated.

 

[HawkRod]

First and most simple: Turn the ignition to the on position and unplug the fuel gauge wire from the sender and ground it. (Make SURE you are grounding it to a good, known ground, otherwise your testing is worthless; don't assume any ground is good. If unsure, run a wire from the negative battery terminal to the wire.)

With the wire grounded, your gauge in the car should read full. If it does, then you have a problem with the sending unit in the tank. If it doesn't move, then you (at least) have a problem upstream.

 

[BeepBeepRR]

By chance is your temp gauge working too? If not then I would suspect the voltage limiter behind the cluster.

 

[Jerry Hall]

Don't ground the sending unit wire for to long or you will burn up a gauge. Have someone help you, just to watch the gauge. As soon as they say the gauge is moving remove the ground. Your other question 10 ohms is full 73 ohms is empty.