Really weird fuel gauge problem on type 44

[Wallace White]

Eyvind -

I read your message below with interest, because my fuel gauge also
stopped working after I repaired the fuel pump. You know the two white
tick marks on the gauge at the empty end, separated by about 5°? The
needle points right in the middle of those, constantly.

I thought I might be having the some problem as you, but alas, it looks
like the sender's arm is simply stuck. Here's a data point, which might
be useful for you or others:

Sender resistance: 230 ohms (I think)
Gauge readout: between empty ticks (as above)
Voltage across sender, measured by cutting the wires' insulation: 8.3 V
with sender connected, 9.9 V with sender disconnected

This suggests that the gauge circuit means that full reads 0V and empty
reads 10V (I think the Bentley says full is 60 ohms and empty 450 ohms.)

The tip-off that the wiring is okay on my car was that, when I
disconnected the sender, the gauge fell all the way to the leftmost
white tick. So it's working--it's just stuck.

Hope that helps... have you had any luck with yours? I'm getting used to
  watching the trip odometer plus the mileage computer...

- Wallace
   '87 5kcstq 192k

Eyvind Spangen wrote:
> The fuel gauge in my '86 100q doesn't work. It quit after I changed
> the fuel pump.
>
> When I turn on the ignition, the gauge just sits just below the red
> part. But - the weird thing is - when I use my multimeter to measure
> resistance on the terminals on the top of the fuel tank, I get the
> correct resistance. I had about 1/2 full tank, it indicated 320-330
> ohms. I filled up and got around 650. It looks like the thing inside
> the fuel tank is working.. If I brigde the terminals on the cable
> going to the gauge, it goes right to top. It looks like the gauge
> itself and the wiring is OK too.. Then I tried contact cleaner, no
> difference.. I even installed two wires between the gauge terminals on
> the tank and the connector, nothing happened..
>
> Anyone have any tips? I don't understand what can be wrong now..
>
> --
> E. Spangen
> '86 Audi 100 2.2 CS quattro
>