Oldsmobile/Buick Repair: fuel gauge, negative battery cable, olds aurora

Question
     My "99" Olds Aurora 4.0, fuel gauge is fluctuating between empty and full while the engine is running. I assume that it has somthing to do with the sending unit.If so I would like to know the location of it and maybe some of the procedure of the repair so that I can determin if I can do it myself or take it to a repair garage. (I am handy with tools) And maybe a cost estimate on parts. And also a labor estimate.Thank you so much for all your help.         Rick  

Answer
Hello Rick,

Actually, it looks like you can replace it through the trunk. Here are some instructions I found. I would still look up the gauge and sender test proceedure.


REMOVAL & INSTALLATION
Before servicing the vehicle, refer to the precautions in the beginning of this section.
Relieve the fuel system pressure.
Disconnect the negative battery cable.
Drain the fuel tank with a hand held siFID n until the level is less than 1⁄4 full.
Remove or disconnect the following:
Spare tire and jack
Floor trunk liner by pulling it back
Fuel sender access cover
Fuel sender assembly quick connect fittings
Fuel sender assembly electrical connector
WARNING
When the lock-ring is removed from the fuel sender, the sender assembly will spring up. Downward pressure should be kept on the assembly and slowly released to ensure the sender assembly does not get damaged.

Lock-ring from the fuel sender using tool J-39765 or a spanner wrench
Slowly release the spring pressure on the sender.
CAUTION
The reservoir bucket on the fuel sender assembly will be full of fuel when it is removed from the tank. Be sure to have a catch pan nearby to drain the sender into.


Remove or disconnect the following:
Sender assembly from the tank
NOTE: It will have to be tilted slightly about half way out to be sure the fuel level float clears the side of the tank.

To install:


Fig. 1: Fuel pump and sending unit module assembly




Install or connect the following:
New O-ring on top of the tank
Sender assembly into the tank
Retainer on top of the fuel tank, compress the sender until the retainer can be engaged; then, lock it in place with tool J-39765
Quick connect fittings to the fuel sender assembly
Sender assembly electrical connector
Negative battery cable
Pressurize the fuel system and verify no leaks.
Install or connect the following:
Fuel sender access panel
Trunk liner
Spare tire, jack and spare tire cover
Refill the fuel tank.

Van