fuel gauge going mad??

[sajid1]

right my fuel gauge has started to play up, it flickers from empty to full and sometimes just falls to empty etc when driving

when i turn my ignition on it reads full, --when there isnt a full tank of fuel

the reserve light works as does everything else on my clocks

i have recently replaced to fuel pump for a second hand one
i thought it was the sender unit which comes with the fuel pump, i have changed 3 of these but no luck,

i have also changed the Si board and used my original dials, no luck
i have used my orignal Si board and just replaced the fuel gauge but still no luck, also tightened the nut on the back of the gauge

the closest i have got to finding the source of problem is this---
on the passenger side of my car under the rear seat, there is a round plastic cover, when removed it reveals something which looks like the fuel pump, but i know that the fuel pump is on the drivers side

maybe this is the return unit or something, anyway
if i unplug this and turn my ignition on, the fuel needle doesnt move at all, and my reserve light still works ( fuel is on reserve)
is this faulty then or is it something else


thanks in advance for any advice??

[Brianmoooore]

The sthing you have found is a level sensor for the left side of the tank. This is connected in series with the one in the fuel pump.
As a check, pull the plug of this, and arrange a short circuit between the two pins of the connector.
If this gives consistant, although excessive readings on the gauge, then this sensor is faulty.

[sajid1]

ok thanks, will try this and get back to you