RGS and RGS Corsa Electronic Fuel Guage Service Information.

Panel guage calibration marks

1 = 10 ohms

3/4 = 51 ohms

1/2 = 98 ohms

1/4 = 144 ohms

0 = 240 ohms

pointer at rest ( minimum deflection ) = 540 ohms

Test procedure
If you borrow a resistance decade box and connect it to the Dark Green
wire and the Red/Black wire this will drive the panel gauge
(disconnected from the sender of course ) ignition on.

The yellow light is driven by the Red wire and if connected to the Dark
Green wire it will light, i have set this to come on at O on the fuel
gauge, it is adjustable on the sender unit.

Sender unit will drive the guage on this Corsa with the following data;

pointer at rest on bottom stop = 2.4 Litres in the tank

0 = 3.6L

1/4 = 7.7L

1/2 = 10.7L

ran out of time to finish the calibration.....

actual sender unit Resistance when arm is in the following position

Lower stop = 340 ohms

Mid position = 96 ohms

Upper stop = 12 ohms

Mechanical Fault, check the rivits holding the sender unit inside the tank for loosness as
this is the return path for the sender signal and needs to be secure for a stable reading
on the road.