fuel gauge problems

Post by **dennis** » Thu Jan 01, 1970 1:00 am

Hi
I am hoping some one can help me on this little problem with the fuel gauge reading on my van.
a little while ago the fuel gauge would only read to half full, so i did the usual check of earthing the fuel gauge wire to earth and the fuel gauge registered full so would appear that the gauge and voltage reg were ok.
so i fitted a new tank sender unit, but the gauge will still only register half full.
Now when i get the old sender unit and connect the fuelgauge wire to it, put the sender unit to earth and move the plastis bob which moves the resister then the gauge will work fine i.e, when the sender unit is at the top so making it so it should read full then the gauge registers full and when the unit is moved to the bottom of the resistance then the gauge registers empty.
The sender unit in the fuel tank at the moment is a new one, have i done anything wrong when fitting the new one.
thanks
dennis

Post by **dennis** » Thu Jan 01, 1970 1:00 am

sssssome one must know the answer please help

Post by **newagetraveller** » Thu Jan 01, 1970 1:00 am

Sorry but we need a little time to think about this one.

Post by **Willie** » Thu Jan 01, 1970 1:00 am

Lo, well,on the face of it it would appear
that when you deliberately earth the sender
wire the gauge reads as it should do,i.e.full
when you restore it to normal the gauge does
NOT read full. this suggests that the petrol
tank,or the sender plate which is screwed to
the petrol tank is not a full earth?? This
is valid unless when you short the sender lead to chassis you are doing so on the petrol tank itself??
willie

Post by **dennis** » Thu Jan 01, 1970 1:00 am

Hi
I am shorting the sender unit on top of the new one which is bolted to the tank, also works the same when shorted out on the tank.

Post by **Willie** » Thu Jan 01, 1970 1:00 am

Oh, thats sorted that theory! The only thing
I can suggest now is that your float on the
sender is not correct so that it does not
rise to the correct height in relation to the
amount of fuel in the tank?? Not very likely
but since it works on a full short to chassis
it obviously IS'NT reaching a full short when
in situ
Willie

Post by **dennis** » Thu Jan 01, 1970 1:00 am

thanks to every onr on this matter.
will try what you say and report back.
dennis

Post by **newagetraveller** » Thu Jan 01, 1970 1:00 am

I agree with Wille on this one.
I would like to know what your petrol gauge reads when the tank is:
a. three quarters full
b. half full
c. one quarter full
To put it another way,
(1) if you fill the tank from empty, when the tank is half full has the gauge reached the half-way mark and does it stay there while you completely fill the tank
OR (2) is it reading one quarter full when the tank is half full and then goes up to the half full mark when you fill the rest of the tank?

[ This Message was edited by: newagetraveller on 13-05-2002 10:52 ][ This Message was edited by: newagetraveller on 13-05-2002 10:54 ]

Post by **dennis** » Thu Jan 01, 1970 1:00 am

hi all
i think i may have cured the problem.
i did not realise the sender unit bob had to go to the bulge in the top of the tank, i think i fitted the new one in the wrong position.
when full the gauge now reads full hoping this is the answer.
will report back if all is ok.
many thanks to all.