Fuel Sender

[Guest Taffy Rob]

Hiya, Im running a 2b with the Vicki green loom attached, and am having problems with the fuel gauge.

It did work at first, but has since failed (and so always read empty), in fact this was the first time I filled the tank up. As far as the loom goes it replicates exactly what the sierra one does, i.e. you have a feed from the sender to the gauge (which is the top right one i believe if you look from behind?), and an earth from the other terminal on the sender unit. There is power to the gauge, and the temp gauge which works off the same source is fine. And I have tried a spare gauge I had in the garage, with no luck.

I have checked the wiring and cannot find any fault, although thats not to say its not the problem!

What Im after is how the gauge works? At first I thought the sender was just a rheostat, however if you connect a lamp to the output of the gauge (and then to earth) you get neither a shiny light, nor a reading on the gauge. So does it measure resistance instead? Or have I got two duff gauges?

Please help as its doing my head in...

Cheers

Rob

[Longboarder]

I thought the sender was a rheostat and is supplied from position 6 on the instrument multiplug which is the wire from the fuel gauge. If you are using the Ford plug to stick in the top of the sender unit the wire is brown/black or maybe blue/black in the 2.o'clock position viewed from behind so you have the right one. The Bn/Gn and Bn/R were wires to the fuel computer. I have 9 volts at the sender end of the Bn/Bk which comes from the gauge output. (I wouldn't take this reading as correct as my voltage stabiliser doesn't!). I guess you must have a bad connection to or from the gauge or a duff gauge if there are no volts setting off from the gauge.

 

Nigel

[Guest Bernie]

To check the gauge disconnect the wire from the sender and make a good connection to a convenient earth point. It should go full scale if my memory serves me right. Take the earth off and the gauge will go low scale. If the above happens then your problem is more than likely with the sender. If not it's either the wiring or the gauge. You could try repeating the test at the gauge end by shorting the gauge input to earth with a short piece of wire, that would eliminate or prove the wire from the sender to the gauge as being suspect.

 

The sender I have is resistive. I'm not sure of the exact figures, and I may have the gauge movement a about f, but they are of the order of 0 to 120 Ohms, full to empty.