Need to Replace Your Fuel Tank Sending Unit?

If your gas gauge has been acting boinky, or worse you're running out of gas on a regular basis, you might need to replace your fuel tank sending unit. Sounds bad, but in most cars it's fairly straightforward to replace a fuel tank sending unit (also known as the fuel sender). Check your manual, but if your car has a fuel tank sending unit located under the rear seat, where a large percentage of fuel senders are accessible, you're in luck. It's easy! We'll show you how to replace your fuel tank sending unit with ease.
What You'll Need:
flat head screwdriver
Phillips head screwdriver
hammer
open end wrenches
replacement fuel tank sending unit
Getting to Your Fuel Tank Sending Unit

Before you begin, disconnect the negative battery cable to be sure no electrical sparks are possible. You're dealing with gas which is highly flammable!
Your fuel tank sending unit is located in the top of the fuel tank, but is accessible under your back seat (or under the carpet in your trunk). The sending unit will be protected by an access cover, usually held on with a couple of screws.

Lift your back seat or trunk carpet and locate the access cover for your fuel tank sending unit. Remove the screws holding the cover in place and remove the access cover to reveal the fuel tank sending unit.
Removing the Fuel Tank Sending Unit

Safety Note: Gasoline is highly flammable. By removing the fuel tank sending unit, you are opening the gas tank. Be sure there are no sources of spark or flame nearby.
With the access cover removed, you'll see the fuel tank sending unit right there on top. It will have a wiring harness plugged into the top (this tells your gas gauge how much fuel is in the tank).

Unplug the wiring harness and move it safely to the side. If your fuel tank sending unit is screwed or bolted in place, remove the screws or bolts.

Some sending units are a "twist-lock" type. They work like the old twist-lock gas caps. You'll see a few notches along the outer ring of the sending unit. Place the tip of a sturdy flat head screwdriver in the notch and gently tap it counter-clockwise. The sending unit will rotate until it's loose. (the picture above shows the fuel tank out of the car to illustrate the fuel tank sending unit's location).

Now you can remove the fuel tank sending unit in one piece. Attached to it is a long rod with a float at the end, so you might have to try a couple of different angles to get it out.

As usual, installation is the reverse of removal. Don't forget to plug the new sender in or it won't send you anything!