The gas gauge in my '99 Buick Park Avenue Ultra has gone insane: once the tank’s anything less than three-quarters full, the gauge starts jumping between full, empty and an actual reading at random intervals. This wouldn’t be that much of a problem EXCEPT that this car has an alarm that goes “bong-bong-bong” every time the needle hits the “E,” which can be several times a minute.
It’s almost certain that the problem is in the sending unit, but I really don’t want to pay big bucks to drop the tank and replace what I think is a module including both the sender and the fuel pump. This is an old car with a lot of miles. Further, the “driver information center” includes both a trip meter and a gallons-used-since-last-fillup readout, so I don’t really need a working gas gauge. What I need to do is shut down that stupid alarm and stop the distracting needle bouncing. In theory, I should be able to either ground or open a wire someplace… but which one? Anybody got a clue where there’s a convenient gas gauge sensor lead? Failing that, does anybody know where the annoying alarm speaker is? GM is incredibly good at hiding these things…
I would locate and unplug the alarm. A service manual might help you find it, but you can also just follow your ear. First, of course, you have to get the alarm to sound continually, which might not be so easy.
Are you sure you have to drop the fuel tank for access to the pump and sender? Some vehicles have an access door above the tank.
Another thing to consider is a bad ground on the gauge. Maybe it’s intermittently making contact?
Drop the tank and put in a new sender and pump, This is like getting a dent in your car and not getting it fixed,it starts a downhill slide.
The alarm/speaker is to the right of the steering. There are several holes in a circular pattern. Taking this part of the dash off is easy. Take the left side of the dash off first. Pry the imitation wood strip off and remove the screws. Same on the left side of the steering wheel. Keep in mind disconnecting the speaker wire prevents other alarms to go off too.
GM has a special cleaner that you put into the gas tank that is supposed to clean the contacts in the sending unit inside the tank. Make sure you get the one that says “plus” on it. I believe it is available only from a GM dealer. Apparently what happens is that the contacts get crude on them, and this cleaner is designed to clean them off.
Usually On These, The “Wiper” Part Of the Sender Has Little Fingers That Disintegrate, I Believe
I Agree With McParadise About The Sender Access, Check The Trunk … I Know 00 - 05 Has One
Like Psanzone mentioned you could try filling a couple tanks of gas with a cleaner to see if that cleans the contacts. Some folks have fixed the gauges that way. Cheveron has a product called Techron and is a lot less expensive than the GM product and may be the same thing, rebadged.