Dead fuel gauge!

[ChevyMan]

I have a 2001 2500HD Duramax with 65k miles. Two weeks ago my fuel gauge suddenly went to empty and stayed there. The tech at chevy tested the gauge and it showed to be working. He said that if my fuel gauge wire was grounded it would show empty and if the wire were open it would show full. I pulled the bed off (Much easier than dropping the tank) and unpluged the tank sensor. The gauge still showed empty (Grounded).
Anyway, the question is - Does anyone know the wire path for the fuel gauge sensor? Any help is appreciated.

[FirstDiesel]

The gauges I've worked with don't work like that.
Grounded causes the gauge to read full, open causes it to read empty. I would think it's still the same. Sounds like a broken wire to me. Take the wire off the sender and ground it. Does it change?? If not the wire is broken. I would pull the dash a part and try ohming the wire from the sender to the dash and see if it's broken. Rather than trying to trace and find the break, I'd just run a new wire. JMHO