CLAAS 7F32h – ENG, TR1, TR2, TR3, or A100: Fuel Level Potentiometer Not Connected

The fuel level potentiometer (R35) is not connected, meaning the control system cannot receive a signal to measure the fuel level. This results in an inoperative fuel gauge and the inability to monitor fuel consumption or estimate time before refueling. The underlying condition is typically an open circuit in the sensor's wiring, a disconnected plug, or an internal failure of the fuel level sensor itself.

• Axion
• Arion 510
• Arion 520
• Arion 530
• Arion 540
• Arion 610C
• Arion 620C
• Arion 630C
• Arion 640C
• Ares 546
• Ares 547
• Ares 557
• Ares 567
• Ares 577
• Commandor
• Dominator
• Medion
• Mega
• Jaguar

1. 1

   Inspect the wiring harness leading to the fuel tank and sending unit for frayed wires, loose connectors, or corrosion.

2. 2

   Ensure the electrical connector at the fuel level sending unit (potentiometer R35) is securely plugged in.

3. 3

   Verify the sending unit has a clean and tight ground connection to the tractor's chassis.

4. 4

   Check the fuse for the instrument cluster or fuel gauge.

5. 5

   Perform a jumper test to verify gauge and wiring: disconnect the signal wire (gauge should read empty), then momentarily ground it to the chassis (gauge should sweep to full). If it responds, the gauge and wiring are functional.

6. 6

   Perform a resistance test on the sending unit: measure resistance across signal and ground terminals while moving the float arm. Readings should change smoothly without sudden drops to an open circuit (OL).

1. 1

   Disconnect battery

   Disconnect the tractor's battery to prevent any electrical shorts before beginning work.

2. 2

   Access and clean sending unit area

   Locate the sending unit on top of the fuel tank (remove panels if necessary). Thoroughly clean the area around it to prevent dirt from falling into the tank.

3. 3

   Remove faulty sending unit

   Disconnect the wiring harness, remove the securing screws or retaining ring, and gently lift the old unit out, being careful not to damage the float arm.

4. 4

   Install new sending unit

   Verify the new part matches the old one. Place a new gasket or sealing ring, insert the unit ensuring the float arm moves freely, and tighten the retaining screws evenly to ensure a good seal.

5. 5

   Test system operation

   Reconnect the wiring harness and battery. Turn the ignition on to verify the fuel gauge provides a reading. Add fuel if necessary to confirm operation.