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Mark
Mark, Technician
Category: Car
Satisfied Customers: 1504
Experience:  Qualified City & Guilds
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I have a problem with my deisel gauge. It reads quarter full

Customer Question

I have a problem with my deisel gauge. It reads quarter full irrespective of what is in the tank. We have changed the sender unit and tried a different instrument panel to no effect. Any suggestions?
Submitted: 3 years ago.
Category: Car
Expert:  Mark replied 3 years ago.

Mark : Hello, my name is Mark and I will try help you with this.
Mark : The only logical explanation for this fault is something in the tank is impeding the float.
Mark : You have already established the guage works by disconnecting the plug and it zeros and then when you earth out the signal wire it goes to full. These tests rule out any wiring fault or fault with the instruments.
Mark : You have also ruled out the sender unit by replacing it so all that is left is something inside the tank or the way it has been fitted.
Mark : If you remove the sensor and reconnect the plug and work the float manually and the guage reads ok then the fault is somewhere in the tank or the fitting process.
Mark : Please remember to rate my assistance.
Mark : Thanks.
Mark : Mark.
JACUSTOMER-e2yx4fpj- :

Sorry wehave tried that. We removed the sensor and did as you suggested to no effect.Any other suggestions?

Mark :

What were the results of moving the float to different positions?

Mark :

The next check would be to test the resistance of the sensor and see if it varies when you move the float.

Mark :

After that you should check the wiring connection at the harness for damage or corrosion on the wires.

JACUSTOMER-e2yx4fpj- :

We have fitted a brand new sensor, which we wouldhope had no fault in the resistor but we

JACUSTOMER-e2yx4fpj- :

We have fitted a brand new sensor so the resistor should be ok but we will try. Otherwise wewil

JACUSTOMER-e2yx4fpj- :

Can I ask if the wiring from the sensor is direct and isolated from the other circuitry.Could there be interference from other wiring. We will check your suggestions.

Mark :

There cant be any interference from other circuits because when you disconnect it goes to zero and when you short out it goes to full. Any interference would be present at all times.

Mark :

Did you measure the resistance from the sensor and did it vary when you moved the float?

JACUSTOMER-e2yx4fpj- :

We will try that over the next few days.

Mark :

How did it go?

JACUSTOMER-e2yx4fpj- :

Have been away for a few days so have been able to try it yet. Will let you know asap.

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