Fuel Gauge Adjustment

[Steve Sherman]

After checking with the local Audi dealer it seems that the sender I
have in the tank is the right one.  So I tried adjusting the fuel gauge
on the dash via the adjustment screw under the trim piece.  On my Dash
cluster, this adjuster is frozen, could not turn it either way.
 Probably the right thing to do is to pul the instrument cluster and
take a look, but the fuel gauge being off isn't that bothersome, so I'll
probably put that off for now.

But I was wondering if anyone who has recently had the instrument
cluster out can tell me what that adjuster screw is attached to.  I am
assuming it goes to a variable resistor that adjust the gauge reading.
 Would a small srewdriver in the center have any better luck turning
that var resistor?

TIA