fuel guage working in reverse

[minor57]

as the title says my fuel gauge seem to be working in reverse when i put petrol in its moves towards empty. any solutions?

[MarkyB]

Swap the connections?

[Trickydicky]

Whats changed? has it suddenley started to do this?
If it has then I would suspect a faulty sender unit

Richard

[bmcecosse]

I suspect the battery polarity has been reversed - has it??

[minor57]

converted to negative earth a few weeks back yes

[mike.perry]

The fuel gauge is not polarity conscious otherwise it would need changing when the polarity was changed.
What sort of gauge have you got? What colour speedo?
So the farther you drive, the more petrol you have? I wish my car was like that!

[minor57]

er its a smiths gauge in biege from a 1957.

[mike.perry]

No voltage stabilizer to worry about. Check that the green wires are connected to the B terminal and the green/brown wire is connected to the T terminal

[bmcecosse]

The early gauge surely WILL read backwards when the polarity is reversed! It's an ammeter!! Was this when the red light started staying on too - and you 'broke down' ??????????? Did you repolarise the dynamo? Did you swop the coil connections over ? Did you clean the dizzy points or the fuel pump points ? If not - there may be trouble ahead...........

[minor57]

the only time the red light has stayed on when revving is when i accidently pulled the wire off the dynamo and had to be pulled home because niether me or the recovery man noticed it, since the negative earth convertion i have fitted a new electronic dizzy and i completed a 120mile round trip yesterday which is when i noticed the fuel gauge goes up instead of down. the red light turn off the minute i increase the rev slightly and all the wires are correctly arranged.

[bmcecosse]

Ok - but you do need to attend to the points in the fuel pump...... And swap the wires on the gauge...