'Return to sender...(unit)'

[Finn]

I've just replaced my rusted petrol tank and fitted a new sender unit. Trouble is...petrol gauge shows 1/2 full when ignition is on - and does not rise above this - even though it should now show almost full. This is a pre-existing problem - and one I thought I had cured when I replaced the unit. Any ideas...?

Thanks

Finn

[Kevin]

To check if the guage is ok remove the wire from the sender and extend it to a good earth point and if the guage does not deflect fully you know the guage is faulty, check this 1st as it only takes a minute.

[57traveller]

If it's a later black speedometer car, and the test Kevin has indicated proves the gauge, is the voltage stabiliser attached to the rear of the speedometer head o.k? I fried mine some time ago and a known full tank never showed higher than 1/2 to 3/4 on the gauge.

[Willie]

Have you put the sender unit in the tank the wrong way round?
( it could have been in the wrong way round to start with) it is possible
to fit it 180 degrees out so that the float fouls inside the tank and cannot
read full. Assuming that you have a later type with a pushon Lucar
type connector then if you reach in from the rear of the car the
connector should pull off TO THE RIGHT. If it pulls off to the left
you have fitted it wrongly. If that part is ok or you do not have
the push on type connector then we can take it further (an early
type sender will NOT operate a late type fuel gauge and vica versa).

[Finn]

Thanks Willie

Will check fitting and let you know result. I did notice when I 1st began to fill the tank - that it registered 1/4 full(I filled tank in stages) so...will get back to you

Finn

[rayofleamington]

Will check fitting and let you know result

If you take the sender out, then test it thoroughly before putting it back in! You can ground the body of it using something simple like a jump lead - this way you should be able to stick your head somewhere you can see the dashboard gauge at the same time as you move the float up and down.