After installing a new pump my fuel level is reading incorrectly!

Incorrect fuel level readings can occur for a variety of reasons.  

• The most common reason is the float arm is hung up on something inside the tank.  This is generally a fairly simple thing to diagnose by simply removing the fuel pump top hat and inspecting to ensure no lines or wires come close to the float arm.

• If nothing is in the way of the arm itself, you will need to check the resistance reading of the float arm.  To do this you will need the pump out of the tank.
  • With the pump out of the tank use a multi-meter to read the resistance between the two wires.  
  • While reading the resistance, move the float arm up and down to simulate a full or empty tank.  
  • The resistance value should move (relatively smoothly) between 1kOhm (1000Ohm) and 50Ohm (typically).
    • These values are most common and it is possible that your values are different.  
    • Additionally, different cars will have different values for full vs empty.
  • If your float reads correctly, then the float itself is good, and it could be a shorted wire, or possibly the float on the other side of the tank.  Please triple check your wiring and check the float on the opposite side of the tank if possible.
  • If your float reads no resistance, that likely means a broken board and will need to be replaced.