1996 Oldsmobile Ciera Fuel gauge doesnt work

Hi csj1984,

Thank you for the donation.

Possible causes are :
1. Bad fuel gauge.
2. Short between sending unit wire to gauge.
3. Faulty or stuck sending unit.

Unplug the sending unit wireharness and check if the gauge shows Empty when ignition switch is turned ON.

how do i test to see which one of those things it is? where is the plug to the harness for the sending unit? if it is stuck is there anyway to un-stick it or does it need to be replaced?

The first test outlined would confirm if the gauge is faulty.

The harness connector is on top ot the fuel tank, connected to the fuel pump housing.

You would need to remove the sending unit to test if it is faulty. That would require the fuel tank to be dropped.

do i need to drop the tank to access the harness? if the gauge is faulty how would i go about fixing that?

Under the seat there is a connector for the sending unit which can be used for testing purpose. I do not have the diagram for the exact location. Look out for a Purple wire with a Grey wire bunched together.

If the gauge is faulty, it would have to be replaced and might require the instrument cluster to be replaced as an assembly. The chances of the gauge being faulty would be lesser than the sending unit.

I drove the car up on ramps and changed the oil today. When I started it the needle on the fuel gauge moved from all the way past full to near a half of a tank. It doesn't have that much gas in it, do you think it was stuck and will correct itself when I fill it up? What do you think?

Symptoms indicates a faulty sending unit rather than being stuck. The contact for the resistance coil in the sending unit seems to be intermittently losing contact and filling up might get it to work. however when the fuel level drop to the resistance part that is faulty, it might just go to Empty.