I am fixing thing ageter thing my latest 240z. Today is the fuel gauge turn!

It doesn't show any imput? From the sending unit I have 2 wires coming from the unit and one green and one black unpluged? What are they for? Cannot remeber wich is woich but one have male and the other female connector?

Any idea, pict, etc.

The fuel sending unit works like a variable resistor. It changes the resistance on the ground side of the guage circuit. The black wire is a ground, and the other one comes from the guage. You can test the operation of the unit by measuring resistance across the two posts. Mine was not working, I took it out and cleaned it with contact cleaner - it works great now.

I hope that helps a little bit.

Oh yeah, if I remember correctly, the black wire went on the bottom post - but i dont know if it really matters.

The two spare wires (green and black) are the wires Nissan supplied for an electric fuel pump. They are not used on pre-'73 US 240Z unless an electric pump has been added.

Thanks you both...

When you say you took it out? You mean the whole unit? With the tank still on the car?

As for the fuel pump wires... do they have a relay and I can just pop a fuel pump on it or are they just dumy wires?

Thanks you both...

When you say you took it out? You mean the whole unit? With the tank still on the car?

As for the fuel pump wires... do they have a relay and I can just pop a fuel pump on it or are they just dumy wires?

interested as well.....

Do a search for electric fuel pump

http://www.classiczcars.com/forums/showthread.php?t=24026&highlight=electric+fuel+pump

I had the tank out of the car for other reasons. I believe its possible to get at it while its in the car - you might have to just lower it a little bit. This is just a guess because I did have the tank out.