my gas gauge needle jumps from empty to full

check the connector where the harness plugs into the instrument pod. if it isnt loose then try cleaning the contacts on the plug and the circut board, a pencil type of ink eraser works good for this. also check the resistance of the sending unit in the tank with an ohm meter, if you dont have a speedometer cable it is a good chance it is the pod connector too.

ok thanks we will give this a try. I will let you know if it works. I put the wrong year it is a 2000 instead of a 2002. Do you think that will make a difference?

not at all they have the same connection at the back of the instrument pod 94 and earier have speedo cables

I also have a 2000 model and have had issues with my sending unit. When it reads "Full" or all the way t the right that means there is no resistance .As the float moves up and down with fuel level the resistance changes (higher the fuel lower the resistance)So if its "jumping" I would check the sending unit in the tank.The metal contacts failed on mine .So it showed "over full"

Question: I have a 2003 Buick Century and my gas gauge does the same thing and so does my speedometer. What do you think that might be?