[Healeys] fuel gage/sending unit

[Alan Seigrist]

Gary -

You're really not supposed to adjust the guage readings by playing with the
float arm.  You adjust the guage by ... guess what .... adjusting the guage.

This is from an old MGB website (no longer on the web but I know how to get
to it) and the writer's sage advice is:


*Adjustment
*There are 2 slotted holes that allow adjustment of the gauges. Unless there
is a sever inaccuracy, it is not recommended that any attempt is made to
adjust gauges because the two adjustment slots do not work independently
from one another. Adjustment of the slot nearest the low end of the gauge
tends to adjust the full scale reading, while that nearest the high end
varies the minimum reading. It will be found however that getting the gauge
to read correctly at one end also has an effect on the other. Adjusting the
other end then causes the original adjustment to change. Gauges may be
checked and adjusted by applying current from a 10 volt d.c. source through
2 watt resistors or a variable resistor of value shown in the table below.
The approximate resistance required to be in series with the gauge to
produce a given needle position is:.

 <http://web.archive.org/web/20050208010348/>

*Gauge Reading*

Min.

1/4

1/2

3/4

Max.

*Resistance ohms*

320

205

120

85

55

Although he says not to adjust it... I might recommend that while your tank
is empty you adjust the guage so that it reads just at empty.  That way at
least you will always know if you are close to empty.

Regards,

Alan
'52 A90
'53 BN1
'64 BJ8


On 8/23/07, Warthodson at aol.com <Warthodson at aol.com> wrote:
>
> I just received a replacement sending unit & installed it in a new fuel
> tank
> to test the gage/sending unit combination. With an empty tank, the gage
> reads
> 1/4 full. I tested my original sending unit in the same tank & it also
> reads
> 1/4 full, in an empty tank.
>
> FYI, the reason I am replacing the OE sending unit is because the ohm
> reading
> is very erratic as the float is moved. I tried to repair it,
> unsuccessfully.
>
> The depth from the mounting flange on the new tank to the bottom is the
> same
> as my old tank. The old sending unit reads about 16 ohms empty & the new
> one
> reads 22. Both sending units read about 2 ohms when the arm is moved to
> its
> "Lowest" position & the gage reads empty, but the bottom of the tank
> prevents the
> arms from going to their lowest position. If I bent the arm such that the
> reading is 2 Ohms when the tank is empty it will not read full when it is
> full. I
> guess this might be preferable to an empty tank that reads 1/4 full. Is
> this
> a common problem or am I just lucky? What would you suggest?
> Thanks,
> Gary Hodson