Fuel sender help plz

[overrun]

The sender which was in my Escort, was broken. The float arm was spinning around and the float itself was seized - so I binned it.

As we know, it is difficult to find a replacement parts for old toss these days, but I got one. Another two wire type with the same wiring plug as the one I removed, so it connects to the cars wiring loom as it should.

Here:



Old sender for comparison:




The problem I have is that when connected, the sender does not move the gauge.

When checked with the multimeter on the ohms setting, it returns the readings expected and when the two wires on the car loom are bridged, the gauge works.

So the gauge, wiring and sender appear to be fine. Yet they will not work together.

Any ideas? (I have re-terminated the connections on the loom, as one was barely conducting due to corrosion.

I suppose I can also try running a new wire direct from the fuel gauge to the sender and also grounding the other terminal.

[PhilA]

Edit:  Read my own answer and deleted it.

 

Sure the new connector actually makes contact with the plug?

 

--Phil

[overrun]

Yeah. I have bodged a couple of bits of bare wire in to make sure.

 

I am wondering now if it needs to ground via the tank and the ground wire is not enough on it's own? I doubt this theory though tbh and so does my mate.

 

I have a single wire NOS Ford sender that I was wanting to use. Assuming I could connect my gauge signal wire and then it would ground via the tank and work. That never, either.

[twosmoke300]

Yeh prob needs an earth. The 2 wires will be for the gauge and fuel light if it has such modern things

[overrun]

It does have a fuel light. I did assume that would need a wire (as any diagram I see for a three wire sender has the wires down as earth, signal and gauge).

 

I can't be sure the fuel light ever worked in the car, but the two wires coming from the harness seemed to have original connectors on them and there is definitley only two.

 

I am sure that one of the wires grounds on the O/S inner sill, as I was looking for a wiring issue a while ago and I traced them.

Plus, when the two car-side sender wires are joined together, the gauge goes to 'full'.

 

So it must be a ground as opposed to being for the fuel light?

[PhilA]

That makes sense. There'd probably be more wires if it were low-fuel-light also. My GTA has a seperate float switch for the light, the little yellowish cylindder attached with a zip-tie:

 

 

If the new one is switch + sender, I'd suspect it to have to ground through the tank, but looking at it, I'd say it's just sweep arm and windings of the rheostat connected to the two white wires.

 

However, if the wires are backwards and the sweep arm is grounded anywhere on the sender arm.. it would ground both sides and err, the gauge should move to full regardless of where the arm is.

 

With your meter, measuring across the new sender, what does it read, resistance, with the float in "empty" and "full" locations?

 

 

--Phil

[overrun]

Cheers Phil, but it's sorted now.

 

It does indeed ground via the tank. I connected the signal wire from the gauge and left the other wire off and it works.

I tested it by attaching a jump lead to the sender body and grounding it on the car.

 

Will brim it tomorrow and hopefully it does what it should. Threw a gallon in tonight as it was next to empty and the gauge moved as expected.