440 Fuel Gauge Fault

[JAMES FRASER]

I have a 'K' reg 440 1.8I which has a fault with the fuel gauge. No matter how much fuel is in the tank, the gauge will only move a fraction from zero (the fuel warning light extinguishes, however). The sender unit has been tested and is ok. After speaking to the dealer, he suggested that there are two problem earth points on this model which can cause this fault. Both of these were dismantled, checked & cleaned with no improvement. He also suggested that both the gauge itself and the printed circuit on the instruments can cause problems. Both of these have been replaced with no improvement. I am now out of ideas. I suspect there may be a high resistance in the circuit but where? Anyone had this fault or can suggest anything else I can try, I will be most grateful! Thanks in anticipation.

[Paul Clifton]

Have you replaced the printed circuit 'film' or the solid printed circuit board bacause it is usually the board that plays up.
Paul.

[Paul Clifton]

Have you replaced the printed circuit 'film' or the solid printed circuit board because it is usually the board that is faulty.
The other teat is to disconnect the sender wire at the tank and earth it if the gauge then goes to full (don't hold it there too long)the problem is with the tank unit if not the fault is with the gauge circuit.

Paul.

[JAMES FRASER]

I have swapped the whole instrument cluster from a car that was known to be ok!

[Cougar 27]

Im not sure if you car has the digital fuel gauge but I solved
the problem with the 480 speedometer after many nights of cursing at it !. (this may be the cause of your problem)

Some owners have changed the speedometer housing and the sensors
and still have the same fault.

I have pin-pointed the fault to be a dry soldering joint on the wiring harness socket connections on the rear of the speedometer
housing ....after trying everything else !.

The problem I had was my needle held for a short while before dropping back to zero, if I 'tapped' the housing hard enough it would display the speed again but only for a short while.....

But getting back to your point ..........

It was very strange because not only did I get the speedometer working my Fuel Range has changed, when I filled up I had 200 miles on my range. After the repair I have 300 ???? dry joint ???? …….