Fuel Tank Sending Units

Is your fuel gauge reading wrong, or is the needle stuck on empty in your old Jeep? A sending unit measures the fuel level in the tank and sends the signal on to the gauge. Here you'll find sending units from Omix for classic Jeep and Willys models.

What does a fuel tank sending unit do?

The sending unit sits in the fuel tank and typically has a float on an arm that changes an electrical resistance as the level drops. Some versions also have a pickup tube that the fuel is drawn up through. A gauge that is stuck or fluctuates can be caused by the sending unit, but also by the wiring, the ground connection or the gauge itself.

How to choose the right sending unit

• Year and model: the products are grouped by e.g. Jeep CJ 70-83, Jeep SJ 70-79 and Ford GPW & Willys MB 41-45.
• Tank size: some sending units are specified for a 20 gallon tank, so the arm matches the depth of the tank.
• Version: with or without pickup tube, and whether a gasket is included.
• Gauge: the sending unit's resistance range must match your vehicle's gauge – check this for the specific part number.

All products here are from Omix. If you're replacing the tank at the same time, you'll find it under fuel tanks, and caps under fuel tank caps and filler necks.

Installation

Disconnect the battery, work with good ventilation and away from open flames, and use a new gasket. Check the arm's movement before installing the sending unit. You'll find more tank solutions under fuel cells and tanks.

Frequently asked questions

How do I find out whether the fault is in the sending unit or the gauge?

Measure the sending unit's resistance with a multimeter while moving the float. If the value changes smoothly, the fault is typically in the wiring, ground connection or gauge. If it jumps or stays still, the sending unit is the likely cause.

Should the gasket be replaced when the sending unit is removed?

It is recommended. An old gasket is often hardened and can cause leaks or a fuel smell. Some sending units include a gasket, others don't – check the product description for the specific part number.

Why does the sending unit have to match the tank size?

The float arm is adapted to the depth of the tank. If it doesn't match, the gauge can show full or empty too early. That's why some sending units are specified for a particular tank, e.g. 20 gallons, and particular model years.