what makes the fuel gauge needle suddenly drop way down past full?

the body ground may be insufficient now after the corrosion that occurred overnight, Black 1/0 cable from battery should be connected to a bald steel area of the chassis/frame after wirebrushing it clean and the bolt too...and be sure the battery is newer than five years old~ the sender unit needs a solid ground and isn't there~

hahhahaha It never gets old I love it!

you better watch it mister~

let's see if bthomas24 finds it unimportant to have a well established ground, and how to get there....

tell you I am watching. this movie called the italian job, guess what? There are 3 badass mini's in this movie you would love it!

am not sure if I am supposed to be amused or if you are serious based on the back and forth between operator 13 and kbro? I don't understand the "overnight" comment though. I filled up this morning and the fuel needle was working perfectly, it was later in the day when I went to grocery when the needle started acting up (only traveled 8 miles). I will gladly check the battery under the back seat to check the cables. The battery info on the dash says that it is in "normal" range - I have not replaced the battery - could this gauge be wrong as well? I'm a 58 year old mom and want to say thank you to all of you who take the time to help, I have found your site helpful to me many times and am sure I am not the only mom who appreciates your help. Thank you!!

oh, sorry - thought "your answer" meant my answer to what advise was given. Guess I need to go back to the "manual" for the site.

I laugh at his answers cuz he says its the battery 80% of the time not matter what the problem is. I personally dont think its the battery. I think its the sending unit in the tank of the guage malfunctioing. If the battery and/or battery ground was at fault then you would have bigger issues like the vehicle not starting. since it uses alot of amps to crank the vehicle. and not to mention every electrial device on the car uses battery power, it doesnt pick and chose what componet to effect.

yes it does, toast.

Checking the battery, proper ground, in short operator_13 has this issue under control for all. The only thing I am confused by is that no body even mentioned taking a live chicken. Cutting the head off, Then drain, pluck all feather's. Make an incision between, and just under the breast bone's and remove all of the giblets Double check to make sure a fecal matter has been removed, then wash the bird and wash it well. Add salt, pepper, and your favorite seasoning and I suggest slow roast, rotisserie style. After enjoying the entree of what should be a fabulous lunch if your gas gauge issues continue, at that time I would move on to kbro's non-answer(no offence man) I agree that the problem could be the sending unit. But, again, please do not be angry, your response seems a tad short I sure hope some novice, "shade tree" mechanic does not drop the fuel tank, etc. We could have much more than a great lunch with that move.

Little late jdsez last post was 7 months ago. And you havent been around to know operator 13 has multiple accounts and give multiple terrible answers. If the vehicle leaks fluid his response would be clean the battery ground and it will fix all. Its an on going thing and to address my non answer half the people on here never get back to check the questions they ask. Judge roy is one of his other alibi's. You will know if you read any his answers they are all the same.

It is either a problem in fuel pump assembly fuel level sensor card or resitor. Or its going to be a bad stepper motor for the gas gauge in the cluster.

The fuel pump assembly was changed because Gm Has bad fuel level sensors that fail. Not the problem. ended up being that the stepper motor was bad in the gauge cluster. Rebuild by local builder and problem done.