So I'm having some issues with the fuel gauge. From full to half it is accurate. After half it basically goes to indicating empty withing a few miles of driving. Left my place today with a range of 205 drove about 20 miles to work with an indicated level of empty and estimated range of 34. Went to station after work and filled it to full, which only took 19 gallons. Is this the cluster going bad, or the sender going bad?