Are you sure it has a good ground? You should be able to take the wire from the SW gauge and remove it from the tank to see if it reads with power turned on at the key. Then ground the wire and it should go to full on the gauge. If it doesn't move unhooked, or grounded with key turned on, then the problem is at the gauge, not the tank.OK, take me to school. My gas gauge appears to be not working. I wired it just like Stewart Warner says, but when I go to the tank, it does not matter which way the wires are hooked up I cannot get the gauge to work. It has about 5 or so gallons in it so the gauge should be at a little above 1/4. I am working on the little things left until payday when I can get the brake lines.