Fuel Sender/guage problem

[JK240Z]

Hi,

I have just had my fuel tank repaired after it started leaking and putting it back in today have got a problem with the fuel gauge not reading. Took the sender unit out again, tested it and its reading nearly 12v...?? is this right, shorted the wires, still no reading and the wires start getting warm!!

Anyone got any ideas, or wiring info that might help, 1974 260Z 2 seater, by the way.

[Ray Martin]

Hi Jonathan,

Not sure i can come up with any accurate answers for you (electrics aren't my strongest subject!) but i've got a brand new 240Z sender unit you could try if you want? Could bring it to The Lakez Meet at The Heaves Hotel if it helps?

Ray

[Jetaway]

Hi,

I have just had my fuel tank repaired after it started leaking and putting it back in today have got a problem with the fuel gauge not reading. Took the sender unit out again, tested it and its reading nearly 12v...?? is this right, shorted the wires, still no reading and the wires start getting warm!!

Anyone got any ideas, or wiring info that might help, 1974 260Z 2 seater, by the way.

Not sure by what you mean by the sender testing at 12 Volts. It's a variable resistor, not an active component. I had mine out two months ago, and of course didn't save the readings, but I think it varied from 10 to 220 ohms full to empty. Do you mean that it dropped 12 volts across the terminals while installed and with a full, or reasonably full, load of fuel? If the drop across the terminals is exactly the same as from the hot lead to ground, then I suspect a wire became loose or broken in the sending unit. Other ideas:

I think its possible to install the sender upside down which, with a full tank, would produce a large-voltage drop signal that indicates empty.

Lost the ground to the tank? Not sure if there is a strap or something that needs to be hooked up for an electrical connection. Regardless, tank to any other part of the body should short.

Chris

[JK240Z]

Hi Ray, thanks but the sender seems to be working OK. Hope the weathers good for Heaves!!!

Chris, Likewise not the sender we think...?? More work going on today hopefully and I will let you know how I get on....!!!