How to Install a Fuel Sender

A stuck fuel gauge can be a sign of a faulty sender.

When your fuel sending unit fails, it can appear that your fuel gauge is stuck. Since gasoline has been reformulated, some mechanical sending units have floats that swell up and get stuck at a single level, regardless of the level of the fuel. New fuel senders come in two styles: the traditional float in a tube style, or one that measures the electrical resistance of the fuel. Installing the sender is a straightforward process, and many vehicles have a built-in access panel above the sender so that you do not need to remove the gas tank.

Things You'll Need

• Screwdriver
• Crescent wrench
• Ammeter
• Gasket

Instructions

1. Disconnect the negative battery terminal with a wrench. This is a safety measure to prevent any accidental spark while you are working with the fuel system.

2. Open the access panel to the sending unit with a screwdriver or wrench, depending on the style. If there is no access panel, unbolt each clamp and fastener securing the tank, remove the fuel neck tubes leading into and out of the tank, then remove the tank.

3. Connect an ammeter lead to the positive wire leading to the sending unit and the "sdr" post of the fuel gauge, and turn the meter on to verify that the wiring is not faulty. If it has a short, replace the wire.

4. Remove the five screws that secure the old sending unit to the fuel tank. Slowly remove the sender and the gasket so as not to spill any fuel, and set it aside. Keep the screws in a secure place.

5. Place the gasket around the opening, lining it up with the five screw holes, and slide the new sender in place. Screw the five screws back in to secure the new sender.

6. Connect the positive wire to the positive terminal and the negative wire to the ground terminal. Use spray-on electrical insulation on the wire connections to prevent any shorts.

7. Close the access panel and reconnect the battery cable. Turn the ignition on to verify that the new sending unit works properly.

Tips & Warnings

• Never smoke while working with fuel systems.

References

• DIY Boat: Tank Senders Troubleshooting
• Chevy Trucks: Troubleshooting Your Gas Gauge