I need help with a gas gauge problem. My guage will not go above 1/4 tank even when full. When you disconnect the sending unit it will go to full. I have checked the ground at the tank and replaced the sending unit. I have hit a brick wall. Anyone have any suggestions? Could the guage be bad? Loose ground somewhere else? Suggestions welcome! :wacko:

Get a 100-ohm resistor. Unplug the tan wire in the trunk to the sending unit. Connect 100-ohm resistor to the body harness tan wire and ground, simulates full tank.

If gauge works, then check ground wire at sending unit to body, pass side tank strap location. And using ohmmeter, measure resistance of sending unit to ground. Ninety ohms = full, 45 ohms = 1/2 tank.
If gauge does not work, measure voltage at tan wire, both at gauge, at kick panel connector, and at trunk, Should read the same value at all places, until resistance/sending unit is plugged in place.
If gauge does not work, slap dash, needle may be stuck.
If gauge still does not work, use ohmmeter on DIODE scale and measure across meter terminals. Gauge should indicate.