I have a 1994 volvo 940 and the fuel gauge shows empty when full and the low fuel light comes on . also the gauge starts to work as the tank gets empty or tries to work and the lights goes out .

There is a sending unit in the gas tank, just a float attached to an arm moving a variable resistor. you need to pull the tank and replace it. given the age of the car and the labor required, you should also replace the fuel pump while you are in there if that year had the pump inside the tank. i would also call around to fabrication/machine shops and see if any of them can flush the tank. you would be surprised at what accumulates in there over the years.

Good day,

The problem is from the sensor which connects to the fuel gauge located at in the fuel tank,hence it malfunctions by giving a false reading in the fuel gauge display in the dashboard.

The solution is to replace the sensor in the tank,but its kind of technical,but if you are mechanically inclined you can follow the solution provided below;

STEP 1 You might consider step 5 at first before you proceed to drain out all the fuel in the tank firstly by loosen out the bolt underneath the fuel tank(fuel tank is located under the car,beside the back right tyre)

STEP 2 Remove the fuel tank,by loosen out the clips from the bungs that connects to the fuel filter which leads to the engine and the bolts that connects the absorbers.
STEP 3 After removing the tank,you will find a big white plastic which is similar to the plastic in your water closet system tank in your toilet.which is found at the edge of the tank.

STEP 4 The sensor to be replaced is a small green rubber in form of an elastic ring found at the top of the white plastic removed from the fuel tank.

STEP 5 The problem ought to be solved after the replacement of the sensor,but if the problem persists,it implies you might have to check the fuse of the fuel gauge,probably the fuse needs to be replaced.


Have a nice day ahead.