Since i've owned my truck, I have had a faulty gas gauge. When you turn the key to the "on" position, the needle shoots acossed passed the full mark. I've replaced the gauge with the same results. I also replaced the wire harness under the dash, same thing. Then I pulled the Sending Unit from the gas tank, and checked it with an ohm meter, no reading. I hooked the Sending Unit back up, and now I have not seen the needle move. Right now there's only a half of gallon of gas in the tank, shouldn't it still read though?
If your gas guage goes to full as soon as you turn on the switch then it has short in the system.If it does nothing then you have a bad sending unit.The sender should ohm out at 0-30 ohms moving the lever up and down.
The easiest way to figure out if it is the sending unit or the wiring/guage is to pull the wire off of the sending unit and ground it out to something. If the guage pegs out at full, then it is in the sending unit. If it does nothing, you either have a faulty guage, or an open somewhere in a wire. Skippy
Hey guy's I did what you said, and the sending unit wasn't working. So I bought one from Chevy Duty. David
