Fuel Gauge stuck on full even with the battery disconnected

I have spent several days learning about the gauges on my CJ6. However after replacing both and getting to work great after figuring out ground it paramount.......

I know have a new problem the fuel gauge is stuck on full even when the switch it off the battery is disconnected...any idea what is causing this.......

 

Forgot to mention I have checked all grounds with a test light. My next step I think will be to take the dash apart (again) and test the gauges with a meter.....

 

If it stays pegged on full with no power from the key, two things come to mind. Power lead is hot all of the time (Assuming your tank is full) or the gauge is shot. I am leaning toward the latter.

 

when replacing the fuel gauge there are different tank senders that the gauges work on. They do not all work together. Some are opposite each other. You need to measure the ohms of resistance and compare it to the rated input for your new gauge. Check your tank sender for appropriate connections.

 

It is very likely that you will have to remove the gauge to visually access the stuck pointer. I have seen this happen before. There is more than one thing that can cause this to happen.