Gas guage shows full after charging batery

Make sure dash guage is working,,," moves when key is turned on,,,,The sending unit in the tank is bad or has came disconnected,,,it will need replaced,,, if it shows full bad sending unit,,, if it shows empty the ground wire is off or damaged,,,,,unless the guage in the dash is bad,,, chevy has had a world of problems with there dashes,,i would think its the dash guage

sounds like fuel pump is good the floater may need replacing or the wire that reads the floater may be loose

the problem is caused by a defective gas gauge sending unit, this part is located inside the gas tank, you must remove the gas tank to replace it.

should be a grey wire going to the top of fuel tank connects to fuel guage / when the guage in the tank reads grounded it shows full , no ground it shows empty. if you ground that grey wire and the guage jumps to full then faulty guage if nothing maybe bad ground on the tank itself. the guages are a reostat like a tyco race car gun the more it moves the more it grounds .. good luck

Hi

The most likely cause is that the fuel sender in the tank is faulty or that the wiring to the sender is bad.

Less common causes are a faulty fuel guage or circuit in the instrument panel.

Test the sender as it is the most likely cause and easiest to eliminate.

First inspect all connections that are readily visible to insure that they are secure & free from dirt or corrosion.

Disconnect the fuel tank sender wire at the tank. The guage should continue to show full (ignition on). Ground the wire from the sending unit at the fuel tank to any good grounding point on the car. The gauge should go to "Empty". If it does this is a strong indicator that the sending unit is at fault.

Hope this helps. Please do rate my answer. Thanks

Put a volt meter on the battery itself and take a reading when it is doing that. If charge rate is over 14v the alternator may be working but the output is not being cut down to "useful voltage" You may have a regulator problem.

gas tank float needs replacement

Hi
We have the same truck that does the same thing.
The fuel sender in tank is faulty. It is in your gas tank. Common chevrolet problem.

Your needle moving from empty to full and then back to empty indicates that it is trying to set itself (most cars do this each time they are started). So, yes, there seems to be a problem with the sending unit that feeds information to your gas guage. Prior to cracking open your fuel tank, you might try tracking the wires from the back of your guage as far as you can towards the tank. Then track the wires from your tank as far as you can toward the guage. Watch for damaged wires and/or loose connections as you go.

yes. the fuel sending unit in the gas tank does need to be replaced