my fuel gauge was working fine and then somehow I left my key on for about a week or two and the gauge now pegs below empty when I turn the key on and power goes to the gauge. I am thinking maybe the sending unit needs to be replaced. has this happened to anyone before?
seen it a million times. its the fuel sender. if there was a open short in the wires it will peg the full mark. empty 99% of the time is the sender. pull it out and plug it back in out of the tank and move the float up and down and see if the needle will move on the gauge. ive also seen the float fall off the rod and there for it wont raise and lower the sending rod to the gas level. good luck
^^^ What he said. Additionally, if you want to confirm that it's NOT your gauge, you can usually ground the gauge (just enough to watch the needle sweep across). If it moves, it's the sending unit that's bad.
yep it was the sending unit, took it out and had no change in resistance across it as I moved the arm. I also checked the gauge by jumping the two wires from the sending unit together and the gauge jumped to full. I picked up a universal sending unit off amazon, for $30 with 2 day shipping