I get more confussed the more I read what "Haynes Sez", You have a large
difference in the resistance reading which should be correct. I would
not suspect the sending unit is bad. If the unit is out, ground it to
the dash and run a jumper from the sending unit to one side of the guage,
should now be able to move the float assy. and watch the guage change.
If it does not change, check for voltage going to the GUAGE, should read
12V. If the voltage is there, I would say you have a bad guage. Becare-
ful not to short out the 12v going to the guage and only use the output
side of the guage.
----------------------------Original message----------------------------
On Wed, 12 Jul 1995 ciaffone@nando.net wrote:
>> I do not remember what the resistance is on the sending unit, but
>> believe it is high and will change with the amount of fuel you have in
>> the tank.
> ----------------------------Original message----------------------------
> I am trying to debug a faulty fuel guage/sender.
> Symptoms are:
>
> 1. Turn on key, guage climbs slowly to E
> 2. Disconnect wire at sender, guage returns below E
> 3. Earth wire from guage at sender end, guage
> climbs to F.
>
> My guess is that I have a faulty sender or float.
> Is this a correct diagnosis??
>
> Haynes manual sez that a disconnected lead causes false
> F reading, while grounded lead results in false E reading.
> This seems backwards. Which is right?
I just brought my sending unit in (no I didn't pull it just to reply.)
and the values for resistance are.
(roughly, digital meter bouncing +/- .2 ohms)
216 ohms at one stop, and 14 ohms on the other.
I couldn't find any specs in my Haynes, and I bought the car in boxes so
wether these are correct will wait until I get the interior back in.
(RH floor pan to be welded in Friday, interior put in Saturday, engine
running next week. Thats the stuff dreams are made of)
Eric
Eric L. Van Iderstine - ME - Mississippi State University
elv1@Ra.MsState.Edu http://www2.msstate.edu/~elv1
74 MGB & 85 Buick (until I finish the MG)
"An object at rest cannot be stopped." The evil midnight bomber
what bombs at midnight FROM "THE TICK"
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