Fuel guage.

[bsweet]

Having trouble with my Minor 1000 fuel guage reading, as even with a full tank it reads low.
Being an electrician I would have thought this would be simple to fix.
Can anyone correct me if I am wrong but I would have thought if there is a negative to the guage (mine is pos. earth again) and the other side is earthed via the tank sender then it should work. By shorting the wire at the tank to earth the guage should read full scale.
As I had no joy doing this I tried setting up a couple of spare guages on the bench with a spare sender unit, but they did not work either.
I,m a bit stumped as none seem to work and wondering that if the guages have been used on a negative earth vehicle, could this bugger them up?
Regards Brian

[Scouse]

Changing from +ve earth to -ve doesn't affect the fuel gauge so it shouldn't affect it going back the other way.

Are you using the original gauge & sender unit ? Later cars use a voltage stabiliser that isn't compatible with the early 1000 like yours.

When you say it reads "low" do you mean it reads lower than it should or it reads empty ?
How's the wire to the gauge ? No resistance at all ?

[bsweet]

Hi Scott,
Using original guage and sender. Wiring is brand new.
Am I right when I say that power to one side of the guage and earth to the other should be full scale. From memory I think there is a small deflection of the guage when ignition turned on.
Regards Brian

[Scouse]

[Triumph Man]

The gauge should have ignition to one side & the other side to the tank sender, the fuel gauge earths through the speedo head so make sure there is no paint or sealer between them, i've had this before especialy if the speedo is just pushed in, not bolted in.
Trev
Aus

[bsweet]

Thanks Trev, I will check that out.
Regards Brian

[Fishmm51]

what voltage should I get at the wire which connects to the tank?

I used a test light not the best but the light is very dull which tells me less than 6volt.
Reason why I ask is that the gauge is only reading half full when the tank is full.

[John Ballard]

I bought a new sender unit as I changed to a black speedo and the old sender was not compatible.
What I did was place an earth V- ( neg) cable from car body to the screw hole of new sender connected cable to terminal and with ignition on bent the float arm to read full when fully up and empty when fully down.
Then I fitted the sender. This is given in the instructions that came with it.
WARNING!
Off course this cannot be done in the boot if the sender is removed from the tank, petrol fumes and electric sparks do not go well together.