Today on the way into town the fuel gage went way past full and when you turned it off it went only down to 3/4. The sweep of the gage was the same only starting at the 3/4 mark. I had just filled it up before taking off. I did not notice it until after putting 50 miles on the tank. I stopped in at the GMC dealer at the Idaho auto mall in Napa before coming home to see if they had an idea. The service writer through out if the interment panel is bad it would be $500 and if it was the sending unit it would be $1000. I just smiled and walked out. Beings the instruments are all ran by the computer I figured disconnecting the battery for a few minutes while checking the fuses would rest it, which it did. I was wondering if anyone else has seen this and if this was a good easy fix or am I in for a world of hurt? Thanks in advance.