Fuel gauge reading full

[7064mop]

I have a new build 1969 Dart that has a fuel gauge issue. As soon as you turn the key on the fuel gauge reads full. Actually past full. I have torn the dash apart, checked the boards, etc.. I have the pulsating light when checking with the test light at the kick panel and at the tank. The temp gauge works as it should. I have taken the wire off at the fuel tank and tested it. The voltage tests there seem in line with what they should be. I have tried grounding the tank but that didn't change anything. Is my problem in my sending unit? It is new but it is a knock off brand. I'm hoping to not have to drop the tank but I feel like that's where the problem lies. I'm just trying to check everything else before I do that

 

[67Dart273]

OK when you disconnect the tank were does it drop? NO? Then remove the left kick panel, and separate the tail harness connector and see if that causes the gauge to drop. If so, there is a short to ground in the wire, in the harness, or mis-wired.

If the gauge does NOT drop with that harness connector separated, either the short wire from the kick panel connector up to the cluster is shorted, or there is something mis-wired, or some kind of problem right in the cluster, and perhaps the gauge unit itself is shorted.

IS THIS a Ralleye dash?

Do the other gauges work OK?

 

[7064mop]

When you disconnect ,the gauge drops to empty. It is not a rally cluster just standard gauge cluster, and all the other gauges seem to be working properly

 

[Ricks70Duster340]

When you disconnect ,the gauge drops to empty. It is not a rally cluster just standard gauge cluster, and all the other gauges seem to be working properly

Disconnect the fuel gauge wire from the tank sender while you have the left kick panel harness disconnected. Put an ohmmeter lead on the fuel tank wire and one to ground. If you have continuity then your wire is shorted to ground.

 

[67Dart273]

Disconnect the fuel gauge wire from the tank sender while you have the left kick panel harness disconnected. Put an ohmmeter lead on the fuel tank wire and one to ground. If you have continuity then your wire is shorted to ground.

Not quite. This is a low impedance circuit. It will show some sort of continuity "normal. Only way you can check that wire is as I implied earlier====separate the kick panel connector, remove the wire from the tank, and then check continuity. That leaves the short length of wire in the harness, from the kick panel to the cluster connector. Will have to pull the cluster.

 

[7064mop]

I unplugged the wires at the kickpanel and I ended up finding the wiring in the trunk was bad. Replaced that wire and the gauge is working. Thanks for the help!