55.2-59 Calibrating the fuel gauge

[BlouDon]

Problem I had was that when the tank was full, the fuel gauge would sit at around 2/3. Measuring the sender when full also produced a reading of around 22Ohm. Applying a 30 Ohm resistor to the wire got the gauge to full, therefore gauge good, sender has an issue.

I removed the sender unit (which looked brand new) and moving the arm to the point where it was reading 22Ohm, it was clear that the arm was physically not moving to the full position. I concluded that the arm was too long so that the float was interfering with the top of the tank.

The arm had two "45º" bends close to the float and I bent these more so they were almost 90º (not quite though). Now the gauge showed full when the tank was full.

Having driven the truck to the point where the gauge now showed empty (needle on the dot near E), I wanted to know how empty the tank really was and siphoned out the remaining fuel. About 10L (2 Gallons) - roughly 30 miles worth - assuming the pickup can access that low.

Now I know the tank is full when it shows full and that I can safely drive it till the needle is on the dot near E and then still have roughly 30 miles in reserve.