Fuel Gauge showing wrong level

[NonMember]

1 hour ago, Paul H said:

the mechanical stabiliser was pulsing from  5 to 10 ish , difficult to read as pulsing was fast . Is this what should be happening

Yes, although the "5 to 10" is a measurement error due to the pulsing being too fast for your voltmeter, probably. Pete's picture is the later, solid state version.