Fuel sender / guage

[Heronscourt]

With 35 litres in the fuel tank my guage was only just off the E mark. I replaced the sender but the needle then failed to move from the E mark. I read somewhere that the orientation of the sender in the tank was significant but am not sure if that is correct. The old sender may have been fitted the wrong way around during rebuild if orientation is significant. If so can anyone advise which way around it should sit in the tank. The temperature guage works so I’ve ruled out the voltage regulator. I stripped the original sender, which by the way is much more substantial than the replacement part, and found that the moving needle was only contacting the first 10 mm of the variable resistance so that has been adjusted and that has now gone in the spares cupboard.
If the orientation of the sender is not significant I guess my guage must be faulty.

[DWW]

Did you test the sender outside the tank by moving the float from end to end while watching the gauge rise slowly? that will certainly help confirm whether the gauge is working correctly.

[44DHR]

Have you driven the car a few miles to check if the gauge then operates ?
I have had a situation before where I have filled the tank and the gauge does not immediately respond to the change in fuel quantity - like on a modern car - but the sender needs the action of moving in the tank for a short distance for it then to move the fuel gauge to the correct higher value. I just put that down to the lack of sensitivity in these older devices.
Regards,
Dave

[rswaffie]

If you think the temp gauge is ok, then swap the connections from the fuel to the temp gauge (or vice versa) and that may rule out a faulty gauge.

[Heronscourt]

Thanks for prompt responses. I didn’t move the float while the sender was out of the tank because it was a brand new sender and because once the old sender is removed the tank is open to atmosphere and therefore vented, oxygen to petrol ratio will no longer be saturated and instructions on the plate on the tank warn to disconnect the battery before working on the fuel electrics. I will try swap fuel guage connections with temp guage at the weekend and post the result.

[RICHOT]

If you're worried about leaving the fuel tank open having taken out the sender to test it - put the replacement one in its place to seal the orifice and then you should be ok to test whether the sender works.

Richard

[Heronscourt]

Thanks for all the input. Actually the problem was indeed the incorrect orientation of the sender. I'd read that the float had to be installed to the rear of the car. I took the sender out and reinstalled it with the correct orientation and the guage worked and the light went out.
The clue was that with either sender the guage didn't move and the light stayed on. If the float had been rising, even if the guage didn't register the light should have been extinguished therefore I guessed that the float was jammed at the side of the tank.

[DWW]

A good result then

[RICHOT]

Glad you got it sorted.

Cheers,

Richard