Question: My Shadow 1 fuel gauge always deflects unnaturally quickly to full and stays there. I have changed the gauge and the sender (from a Shadow 2), the original sender was stuck solid and burned out. I have checked the earths to the tank, sender and gauge. I have checked the test microswitch contacts and as many wires as I can and found no bad contacts and especially no shorts to earth. The low fuel warning light works as does the oil level. What on earth can it be? Regards MW
Answer: The Shadow 1 and 2 senders are different - did you have the same symptoms after you swapped senders? My mechanic's hunch is that the oil level button circuit may be the cause of the problem - do you have a wiring diagram?
Question: Thanks for the reply. Yes the symtoms were the same with either sender, I do have a CD with the wiring diagrams on it but the way they are drawn the circuit is indistinct especially in the way the microswitch cicuit works. would disconnecting the oil level sender help?
Answer: Yes disconnect the oil level sender and see if the gauge moves back. Also make sure the button is operating correctly. Otherwise it sounds like a wiring fault.
Question: I disconnected the oil level sender and no change. I see from my wiring diagram that the spade terminal on the back of the fuel guage supplies voltage to the coolant probe amplifier. I would disconnect the coolant probe amplifier if I had the remotest idea where it is! Incidentally the coolant quantity light doesn't work in service or on test.I am fairly sure the fillament has blown.
Answer: The amplifier is not easy to get to - it is under the top roll in the centre of the dash - it is a yellow colour plastic cube about 2cm cubed.
Question: Thanks for that, I have fixed it! The Shadow 2 sender is not only visually different to the 1 it is totally electrically different too. They are NOT interchangeable.