2005 Lesabre , fuel gauge alarm when full

05 Lesabre, fuel gauge will go to empty and alarm sound when tank is full , usually after stopping at traffic light after fill up. Turn off engine and restart and it goes to full. After that it works intermittently but can't be trusted.

Any suggestions are appreciated.

99 out of 100 times it's the fuel sender......the resistance ribbon on the sender goes bad and you get intermittent connections, which will cause the gauge to fluctuate....

The sender is attached to the fuel pump module in the gas tank......this is accessed though an access panel in the trunk......