The default position with no connection (broken wire, etc.) is full and that's by far the most common. If yours is showing empty either the gauge is stuck (not likely but possible) or the sending unit float is frozen in the empty position. If you are going to pull the tank anyway this is the ideal time to check the sending unit.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.