Re: Sending Unit
Backyard, thanks for the reply. I'm not sure if the gas is causing this or
not, but the arm/float looked fairly clean on the sending unit and all of
the electrical contacts I could see looked clean and unbroken. The only
thing I did not look at was the contact point inside the little metal box
that the float arm moves up and down on. The ground on the sending unit
stops on the other side of the pin contact, so I would have to assume that
it grounds through the fuel tank itself, through the round base plate. Just
to make sure it is getting a proper ground, I have already run a seperate
wire from the frame to the ground pin on the connector, so the ground should
not be an issue now.
I may try pulling the tank down and removing the sending unit later on this
afternoon and then clean it with sandpaper/SOS pad very carefully. You can
take that metal box apart where the float arm moves on the coiled wire, so I
may pull the cover off and see whats in there. I took the old one off the
sending unit I just removed and the coiled wire inside was still in good
shape. There was a bit of dirt in there, but nothing serious, so I doubt
this sending unit would be much worse as it was in twice the condition the
old one was.
It just strikes me as odd that when I had the sending unit out of the tank
and hooked up, it was working fine. And I did not clip a ground wire to it,
I just hooked the connector up and moved the float in my hand. I really
don't think it's the fuel causing this because I've been using the same
brand on two other vehicles for the last 4 years and the fuel gauges in each
"Backyard Mechanic" <email@example.com> wrote in message
> If your gas is causing this, I would change suppliers/brands pronto!
> I think perhaps you didnt look / test close enough when you had it out.
> IIRC, the contact arm is grounded, and the resistance wire is connected
> directly to the sender connector. If the ground is supplied to the arm
> through the pivot that would be my suspect point.
> Solution: very flexible wire, to the arm itself.
> "Sharky" <cleighton@NOSPAM.eastlink.ca> wrote in
>> I'm wondering if it is at all possible to clean the electrical
>> contacts of the sending unit because of the effect of what you guys
>> call "olephins". I have a sending unit on my 1983 F-150 that when if
>> I hook it up outside of the tank and move the float up and down, my
>> gauge will work correctly. However, after a day of working perfectly
>> inside the tank, the gauge all of a sudden stopped working and now I
>> am wondering if it can be cleaned to a state that which it may
>> function again. As far as the unit itself, it is in good condition,
>> no rust or broken contacts, etc. The two male connectors on top of
>> the unit that the round rubber female connector plugs into is in good
>> shape, as is the other connector. This afternoon, I also tried
>> dropping the tank enough to pull off the connector and wire up a
>> seperate ground off the frame of the truck to the sending unit. This
>> did not make any difference, and I have already replaced both wires
>> running along the frame up to the gauge, so I know there is no problem
>> Anyway, can it be cleaned, and if so, what should I use to do it?
>> Thanks for any help